Soldiers were drinking tea when the killer opened fire.

A MANHUNT was under way last night for an assassin who shot dead five British soldiers in Afghanistan.

British troops were involved in the search for the “rogue” Afghan policeman – named by tribal elders as Taliban member Gulbuddin.

Authorities in Helmand Province said he attended a police academy in Kandahar, southern Afghanistan, and had been working as an officer in the Nad-e-Ali area for three years.

Warrant Officer Darren Chant, Sergeant Matthew Telford and Guardsman James Major, from the Grenadier Guards, died alongside Acting Corporal Steven Boote and Corporal Nicholas Webster- Smith, from the Royal Military Police.

Sgt Telford’s uncle, William Ferrand, told the BBC: “It was his job and he absolutely loved it.

“Everybody knows what a wonderful lad he was. It has devastated all of us.”

Prime Minister Gordon Brown paid tribute to the soldiers describing their deaths as a “terrible loss”.

He told the House of Commons: “It appears that they were targeted because they were engaged in what our enemies fear most – they were mentoring and strengthening Afghan forces to make Afghanistan more secure.”

The five servicemen died when the officer sprayed bullets from the roof of the secure checkpoint in Nad-e-Ali yesterday.

Another six British soldiers and two Afghan policemen were wounded in the shooting which has rocked the coalition mission in Afghanistan.

The Taliban has reportedly claimed the attack.

A spokesman told ITV News: “We want to sow mistrust between the Afghan National Police and foreign forces.”

Top UK, US and Afghan commanders expressed regret for the incident and pledged it would be fully investigated.

General Stanley McChrystal, commander of Nato forces in the country, said: “We will not let this event deter our resolve to building a partnership with the Afghan national security forces to provide for Afghanistan’s future.”

The British soldiers had been living and working at the police checkpoint for about a fortnight as part of a team mentoring Afghan National Police officers.

They had just returned from a patrol. Some reports suggested they had taken off their body armour and were drinking tea with their Afghan colleagues.

Without warning, the policeman opened fire from the roof of the checkpoint before anyone could respond.

The killings took the UK death toll since the conflict began in 2001 to 229, and made this year the bloodiest year for the Armed Forces since the Falklands War.

They also threatened to set back progress towards the final withdrawal of foreign troops from Afghanistan.

General McChrystal, said he had received assurances from Afghan interior minister, Haneef Atmar, that the shootings on Tuesday would be “fully and transparently investigated”.

Major General Nick Carter, the British commander of Nato troops in southern Afghanistan, stressed that the investigation would be carried out jointly by foreign forces and the Afghan authorities.