Two British soldiers have been shot dead in Afghanistan by a man wearing the local Afghan police uniform, the Ministry of Defence said.
The soldiers, from 3rd Battalion The Yorkshire Regiment, were killed at a checkpoint in the south of Nahr-e Saraj district in Helmand province.
The deaths follow that of a soldier from 1st Battalion Grenadier Guards who died on Friday after his vehicle hit a roadside bomb.
A Ministry of Defence spokeswoman said: "It is with sadness that the Ministry of Defence must announce the death of two soldiers from 3rd Battalion The Yorkshire Regiment on Saturday 15 September 2012. The soldiers 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 district, Helmand province."
The soldiers' next of kin had been informed, the MoD added.
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 soldier who died on Friday was killed when his vehicle hit an improvised explosive device.
The MoD said the deaths were unrelated to the attack at Camp Bastion in which two US Marines were killed.
The latest deaths bring the number of members of UK forces to have died since operations in Afghanistan began in October 2001 to 430.