Two Gurkhas have been killed in Afghanistan by a man wearing an Afghan police uniform, in what appears to be the latest "green-on-blue" attack on British troops.
The soldiers, from the 1st Battalion The Royal Gurkha Rifles, were shot dead at a checkpoint in Nahr-e Saraj, Helmand Province.
Their deaths bring the number of British servicemen killed by Afghan soldiers or police to 11 this year, compared to just one in 2011, three in 2010, and five in 2009.
The deaths of a British army medic and a Royal Marine last week, alongside an Afghan man believed to be a policeman but not in uniform, is still under investigation.
At least 53 international troops have died as a result of "insider attacks" - where Afghans turn their weapons on their coalition colleagues.
Major Laurence Roche, spokesman for Task Force Helmand, said: "I am saddened to report the deaths of two soldiers from 1st Battalion The Royal Gurkha Rifles who were shot and killed by a man wearing an Afghan police uniform at a checkpoint in the Nahr-e Saraj district of Helmand Province.
"The loss of these soldiers is a huge blow to The Royal Gurkha Rifles and everyone serving in Task Force Helmand. Our thoughts are with their families, friends and fellow Gurkhas at this time."
The gunman is said to have fled after the shooting and is now being hunted.
The two deaths take the total number of UK service members to have lost their lives since operations in Afghanistan began in October 2001 to 437.
They come less than a week after army medic Corporal Channing Day and Royal Marine Corporal David O'Connor died in the same district of Helmand Province.