Two British soldiers have died after they were shot dead in Afghanistan by a man dressed in the uniform of the Afghan local police.
The soldiers, from 3rd Battalion The Yorkshire Regiment, were killed at a checkpoint in the south of Nahr-e Saraj district in Helmand province.
Their next of kin have been informed, the Ministry of Defence said.
The deaths follow that of a soldier from 1st Battalion Grenadier Guards who died on Friday after his vehicle hit a roadside bomb.
Major Laurence Roche, of Task Force Helmand, said: "It is with deep sadness that I must report the death of two soldiers from 3rd Battalion The Yorkshire Regiment who were shot and killed by a man wearing the uniform of the Afghan Local Police at a checkpoint in the south of Nahr-e Saraj.
"The Yorkshire Regiment has suffered a deep loss today and everyone serving within Task Force Helmand will want to send our condolences to the soldiers' families and loved ones at this time."
The MoD said the deaths were unrelated to the attack at Camp Bastion in which two US Marines were killed.
The deaths bring the number of UK forces to have died since operations in Afghanistan began in October 2001 to 430.
Meanwhile, it has emerged that the Taliban attack on Camp Bastion, which left two US marines dead and nine coalition staff injured, was carried out by insurgents wearing US Army uniforms.
Coalition forces killed 14 Taliban fighters and wounded one other, who was then taken into custody.
The offensive took place near an airfield on the north-east side of the base, which houses American forces in Camp Leatherneck.
An International Security Assistance Force (Isaf) spokesman in Afghanistan said: "The insurgents appeared to be well equipped, trained and rehearsed.
"Dressed in US Army uniforms and armed with automatic rifles, rocket propelled grenade launchers and suicide vests, the insurgents attacked coalition fixed and rotary wing aircraft parked on the flight line, aircraft hangars and other buildings."
The official said the six Harrier jets destroyed were US marine aircraft and that two others were significantly damaged. Six aircraft hangars were also damaged.
The Taliban claimed responsibility for the attack on Camp Bastion, saying saying it was carried out because Prince Harry was on the base, and also as revenge for an anti-Islamic film.
He was about two kilometres away with other crew members of the Apache attack helicopters, of which he is a co-pilot gunner, when the attack took place, sources said.
Defence experts said Harry, an Army captain, should not be withdrawn from his military role in Afghanistan, despite the attack.
Tory MP Colonel Bob Stewart, a former commander of British troops in Bosnia, said he did not think the Prince should be pulled out of Afghanistan because of the attack by the Taliban.
"To hell with them," he said. "Harry wants to go there and our soldiers want him there. He should stay."
But Col Stewart stressed the security considerations regarding the deploymentof the Prince were flexible.
"These things aren't set in concrete. If circumstances really change then we'll make different judgments."
He added: "Capturing, killing or hurting Prince Harry would be a huge propaganda coup for the Taliban."