A man shot dead by police as part of the inquiry into Thursday's attempted bomb attacks was not connected to the incidents, police say.

A Scotland Yard statement described the shooting as a "tragedy" which was regretted by the Metropolitan Police.

Two other men have been arrested and are being questioned after bombers targeted three Tube trains and a bus.

In the US, President Bush said the United States and Britain would not be intimidated by "thugs and assassins", while in Pakistan, President Musharraf called for a holy war on extremists, but urged Britain to tackle its own militancy.

Were you caught up in any of the incidents? If you have any photos of the latest incidents send them to yourpics@bbc.co.uk

This debate is now closed. Read a selection of your comments below.

The following comments reflect the balance of opinion we have received so far:

Until safety returns on the Tube, they should drop the congestion charge Rod Watson, Winchester, Hants

Until safety returns on the Tube, they should drop the congestion charge so people can have the choice to travel in a safer manner.
Rod Watson, Winchester, Hants

I was driving a van along the Bethnal Green Rd on my way towards the office in Finsbury Park, North London. I turned onto Columbia Rd, and then onto Hackney Rd, where I saw the evacuated bus with its windows blown out. There were confused looking policemen everywhere, and as I continued on my journey every 30 seconds or so another police vehicle would zoom past at high speed! It's a very uneasy day to be travelling in London that's for sure!
Bob Houghton, London

I was actually on the Shepherds Bush train, in another carriage. I heard a bang then there was smoke, people were panicking. I'm still a bit shaken up from the whole ordeal. I saw everyone trying to get out of the train.
Mo, London, UK

I was on the Northern Line going to my son's school party when the driver said trains were being held at stations but we could not get into Kennington. The passengers were getting irritated after 20 minutes. Little did they know what was happening one stop ahead.
Muqbool Khan , London

It sounds very much like someone was trying to prove how easy it would be to attack again, in a deliberate attempt to provoke fear.
Mari, Scotland

I work on the Tottenham Court Road. People on the street appear to be taking this in their stride. And for as long as this sort of thing continues, will continue to do so.
Anna, London, UK

I work for the NHS and home visit a lot of my patients around the Stockwell, Oval area Gail Lorimer, Watford, England

I work for the NHS and home visit a lot of my patients around the Stockwell, Oval area, and was attempting to visit on the Thursday and Friday of the events, When it usually took half an hour to see these people it took four hours to get from the beginning of Brixton Road to Streatham, and I have also visited the estate where the people were arrested. I have been warned by locals for the last month as I visit these areas. "Be every careful it is very dangerous around here". I know there are a lot of crack dealers but I now think they were talking of other dangers as well. However, we are trying to provide a home treatment service to people in London and now it is becoming too dangerous to visit these people who are desperate for our help. I see this as a deterioration of things to come.
Gail Lorimer, Watford, England

I was on the Northern Line, headed north, and I was at the Stockwell Station when there was all this commotion with this guy with a heavy vest. He ran right past me and all the police came charging after him. I froze for a minute and then walked out of the station. I saw an ambulance come soon after that.
Fred Davis, East Ham, London, UK

I support the action taken by the Met Police in shooting the suspect on the Tube. It is obviously regrettable that he was not directly connected to the incidents but had he stopped and responded to police commands, the tragedy would have been prevented. The police are in a no win situation. Had he been allowed to continue and blown up the Tube they would be criticised for not shooting him. Fair play to our police; they do a tough job and have to make very difficult split second decisions. They deserve our support not our criticism.
Beth, Bristol, UK

The police can't take any risks in the light of recent events Ed Hutchings, London

If you run from the police, into the Underground, jump a barrier and then onto a train, during a state of high alert - then you're going to get shot. The police can't take any risks in the light of recent events.
Ed Hutchings, London

The man shot dead on the train had been followed all the way from an address that had been under surveillance. If he was considered a threat, why was he allowed to get on a bus? Why was he allowed to go into the tube?
Ben, London

I've just heard about the statement that the man shot was not connected to the terror attacks. I hope that this country lends its full support to the officers involved - they had to make a split second decision based on a man who had acted very oddly and run from them even after warnings. We want to fight the war on terror, let's support the men and women fighting that fight.
Jon, Newcastle, UK

So the police say it was a tragedy that they shot an unarmed suspect for the fact that he was running. How can they possibly justify this? Yesterday they were saying that he might be connected with the bombings on Thursday 21/7 yet on Saturday afternoon, they say he was unconnected and a tragedy!
Nick, Harrow

With regard to the breaking news that the man shot was not linked to the attacks on 21/7. As an ex-member of the armed forces, I fully support the police action and cannot believe that the officers involved would not have given a warning. The officers were in a lose lose situation. If they hadn't taken any action and the man had detonated a device they would have been to blame.
Shaun Ritchie, Sunderland

I was on the Victoria line carriage that filled with a chemical smelling smoke after leaving Stockwell on Friday. After evacuating I stayed with police for over three hours answering questions and giving an account of what happened and they seemed to be taking it very seriously. Very few people stayed to give their accounts to police, not even the woman who pulled the emergency alarm who probably had a clearer idea of where the fumes came from.
John, Brixton

My girlfriend was on the carriage behind the one which the bomb took place in on the Aldgate train on the 7th July. It was her 3rd day of her new job in London and despite being covered in black soot and seeing horrific scenes of death, she went back to work on the Monday. Nobody and no religion will change the great spirit of the best country in the world.
Chris, Brentwood

An A-Z is the new must have item to keep in your handbag, ladies Karen, Brixton

I was on a Northern Line train that was evacuated at Moorgate shortly after the incident. Everyone seemed pragmatically resigned to finding an alternative route. Forget the bottle of water - an A-Z is the new must have item to keep in your handbag, ladies.
Karen, Brixton

I still fully intend to go into London to London Bridge later on this afternoon to meet some uni friends I haven't seen for a couple of years. These bombings won't put me off whatsoever.
Alex, Aylesbury

I got onto the Victoria Line train at Brixton, where I suspect that the bomber may have got on. Then just after it left Stockwell tube station, the carriage started to fill up with a strange chemical like smoke which we at first tried desperately to ignore. As the smoke grew thicker everyone started to scream and rush to the ends of the carriage, unfortunately the end that I was at had no access to the other carriage. So we all just crouched down on the floor, praying and waiting for the tube to pull into Vauxhall. Then as the train started to pull into Vauxhall station we all got up and waited to be let off. It was then that I saw the lone red and grey bag seeping smoke, it then was clear to me that this was a failed bomb attack. As the doors opened we spilled out onto the platform running and screaming, but then we calmed down and just quickly walked out of the station.
Karl Hall, London

I have lived in Stockwell all my life and I have not felt so much tension in this area. There are problems with street crime, drug dealing, race hate from black and white people and now we have this. I live opposite Stockwell tube and use it every day and will carry on doing so. To stop would show these people that they have won.
Tony, Stockwell, London

The underground is still the safest form of transport John S, Watford, Herts

As a tube worker having had to deal with numerous security alerts caused by people leaving belongings behind and the knock on effect of such actions, it is pleasing to know that our police force are still No 1. Well done to the officers who dealt with today's Stockwell incident whilst attempting to keep all of us safe. It is an unfortunate escalation of the use of firearms, but in the instances of terrorism that we have all had to endure recently it is a very necessary escalation. By the way, the underground is still the safest form of transport.
John S, Watford, Herts

I flew out from London on the afternoon of 7/7-coming to New York for the summer. It's strange being here with everything going on in what I regard as my home, especially as I lived in Clapham last year - so close to Stockwell. I hope it stops at this. As tough as Londoners are, this must be upsetting for everyone. Security is being tightened now in New York, with police at Grand Central checking bags before you enter the subway-makes the threat feel so much more real out here.
Emily Hewitt, New York (Student in London)

I sit here wondering what is happening in the very place I live and work in. As a daily tube and bus worker for my journey from my home in West London to East London, not only am I fearful of the despicable bombings taking place but also of the added suspicion and scrutiny that I will now be under as a Muslim of Pakistani descent. I am particularly worried for my husband who as part of his job always has to carry a rucksack and works in several locations in London on any one day.
Noreen Hussain, London

I'm a resident of the Portnall Road area and I'm pretty scared to hear that there have been raids there in the last few hours. It'll feel strange going home tonight knowing that this has happened on my doorstep.
Dave P, London

I live five minutes away from Stockwell station, and this morning, my housemate was inside the station as the shooting took place. She was walking from the escalators towards the platforms when she heard the shouts "Police, Police!", at which point she also heard five shots. People coming off the train I believe the suspect was on told my friend that the man had been shot dead by the police, some of whom were in plain clothes. After this, the station was evacuated and it has been difficult to move around Stockwell ever since. There are still no buses running down the Stockwell Road, and I believe a small area may be cordoned off. Police are everywhere, and when I travelled through King's Cross this afternoon I saw them executing random searches, something which is both necessary and reassuring at this uncertain time.
Emma Kidd, London, UK

Police have cordoned off Portnall Road, W9 right angles to the Harrow Road. All residents have been ordered to remain inside their houses. Five gunshots were fired just minutes ago followed by lots of shouting.
Jo Duckworth, London

I was sitting waiting for a north bound Charing Cross train when a Bank train pulled in. I was sitting next to the platform entrance. The train could not leave because a man was holding a set of doors open directly in front of platform entrance. He appeared to be waiting for someone to come through the entrance. Then several men came running in I saw one man had a semi automatic weapon which he was cradling. They all ran on to the next open carriage door as the first man was still standing in the doorway. Then there were three or four loud popping sounds and smoke then two more shots that I saw. The man firing was shooting a person lying on the floor. Then like everyone else I ran.
Joanne Griffin, London, UK

I was travelling with a colleague on the Northern Line from Borough to Stockwell, we then attempted to travel through the station in order to join the Victoria line into central London. Upon arriving at the main concourse between the Northern line and the Victoria line I saw a man run from the escalator towards the Northern line train, he was closely followed by several plain clothed officer, all of whom were armed. The last officer called to myself and my colleague to leave the station, we then heard a shout of 'get on the floor', this was closely followed by 5 'cracks', which at the time we assumed to be gun fire. We then ran to the stairs and left the station. The police were in the process of clearing the immediate area outside of the station. The air ambulance then arrived along with many more police vehicles.
Lee Ruston, Rochester, UK

I was on the Victoria Line tube going north this morning at about 9.15. In the tunnel between Stockwell and Vauxhall we all noticed a distinct burning smell coming from a carriage in front of us (the middle of the train). Passengers started opening the door in between the carriages and walking through into ours. Unsure of what was going on or what they were leaving behind we all stood up and followed suit. There was an eerie silence between us all as we calmly made our way down towards the end of the train. We arrived into Vauxhall station where everyone leapt off the train. I remember seeing a girl, visibly frightened and white as a sheet leaning against the tube wall and as I approached a guy, a stranger, took her hand and kept hold of it, in order to lead her out with the rest of us.
Nina Hume, London

Just had this email from a mate who was on the train:

I boarded the northbound Northern line and sat opposite the doors. A man came in and sat next to me. He took too much space on the seat and seemed on edge - in fact so on edge that I considered changing seats. The guy gets up from his seat and shouts something out of the train from the train door. Suddenly loads of armed policemen come running on the train. Everyone gets up and starts running out. There's loads of screaming. I run out as well. As I walk through the arch leading to the concourse at the bottom of the escalators, I hear gun shots behind me. Then an armed policeman holding a large black gun runs past me. Everyone runs up the stairs.
Charles Clarkson, Leeds

I was at Vauxhall this morning and I'd like to thank a man in a Fantastic Four T-Shirt for keeping me calm when everyone got panicky. He even offered me one of his Wotsits! I know it sounds silly but if you're out there Rich, thanks.
SK, London

People were trampling on me to get to the exit Chloe, Balham, London

I was at Vauxhall in the middle carriage and I heard shouting and screaming coming from the end carriage. I was standing by the door, so people pushed me off the train and I fell to the floor. People were trampling on me to get to the exit. When I finally got up, I ran up the escalators to get to the exit! For a 15 yr old, who doesn't normally travel by herself at all, going to her work experience, I'd say it was a terrifying experience!
Chloe, Balham, London

I was in the train that was evacuated at Kennington this morning. After the police had asked for the doors to be shut, everyone closed books and magazines. I started to look outside on the platform. A man was put on the wall, searched in front of us by at least four policemen. His bag open on the floor, only a glass separating the crowd inside and the unusual event outside.
Arianna, London

I was on the Victoria line tube this morning that was evacuated at about 9.20am. A girl I spoke to outside the station afterwards told me how she was in a carriage closer to the middle of the train than mine, and heard someone shout to pull the emergency alarm. She then saw smoke in the carriage and along with all the other passengers, rushed to try to get into the next carriage whilst the train was still moving. When the doors opened at Vauxhall everyone just legged it off the train.
Sophie, London

I was on the tube at Vauxhall this morning at around 9.15am when all of a sudden people started screaming and running to get out. There was real panic and I thought another bomb had gone off but didn't hear or see anything except screaming. Amidst the panic I saw one woman who had obviously been knocked over. A couple of people stopped to help her but I couldn't believe it when I saw some that seemed to be trampling her.
Dav, Balham, London