What are British troops doing in Afghanistan?

British troops are taking part in two separate missions in Afghanistan.

Operation Fingal is the UK-led peacekeeping mission. Almost 20 other nations have contributed to this operation based in the Afghan capital Kabul.

The second is Operation Veritas, an offensive mission led by US forces against Taleban and al-Qaeda units still operating in Afghanistan.

When did British troops join military operations?

British forces were at the heart of the military offensive against Afghanistan when it began on 7 October 2001.

Today, there are 1,800 soldiers in the vanguard of the International Security Assisitance Force in Kabul.

On 18 March this year, the government announced that it woud be sending ground troops to combat operations as part of the US's Operation Enduring Freedom.

Why have British troops joined the ground offensive?

Early this year, US forces launched a mission to crush al-Qaeda fighters in eastern Afghanistan. However, despite reports from Washington that the bombing and ground operation had killed large numbers of al-Qaeda fighters, other reports suggested that some had slipped the net.

The US then asked the UK to provide specialist mountain warfare troops, prompting speculation that it had indeed exaggerated the successes.

The UK agreed and sent a 1,700-strong battle group led by 45 Commando, Royal Marines, to Afghanistan.

What are they expected to do?

In theory, the mission is simple - seek out the enemy, engage it in combat, eliminate the threat.

But Defence Secretary Geoff Hoon says the country should be under "no illusions" of the risks involved.

"These troops are being deployed to Afghanistan to take part in war-fighting operations," he said.

"We will be asking them to risk their lives. Their missions will be conducted in unforgiving and hostile terrain against a dangerous enemy. They may suffer casualties."

The government has stated that the commitment is not short-term - meaning that troops may be involved in combat throughout the coming summer or even beyond.

When did operations begin?

The first Royal Marines arrived in Afghanistan in early April. Just over a week later, the Ministry of Defence confirmed that some 44 Royal Marines had been involved in a non-combat mission to secure mountain caves.

However, exact details of operations have been few and far between. The only casualties known of so far have been one soldier accidentally shot dead during peacekeeping duties in Kabul and eight others injured in mine clearance.

What do we know of the current combat operation?

Operation Ptarmigan (named after a type of high-altitude grouse) aims to search and clear an eastern Afghanistan mountain valley where Taleban and al-Qaeda forces are known to have operated and may still be hiding.

Hundreds of troops are believed to be involved and defence analysts predict it could become a bloody campaign.

The conditions are extreme. Most of the operation is taking place at least 9,000ft up in the mountains in an environment that is rugged, snowbound and freezing at night.

Are there any objections to the military operations?

MPs from all parties have questioned the strategy of committing troops to both combat and security missions, saying it leaves the peacekeeping troops in a vulnerable position.

Some have criticised the lack of clarity from government on what kind of missions the troops will face and who is ultimately in command, British or American officers.

One regular government critic, the former Labour defence minister Peter Kilfoyle, has raised the spectre of Vietnam, saying that British forces could be sucked into an unwinnable war.

Others have suggested that British troops may be placed in more dangerous situations than American forces because the US public is less willing to accept casualties.