Two British soldiers have been killed in Helmand Province by a man wearing an Afghan police uniform.
The Ministry of Defence said the soldiers, from the 1st Battalion The Royal Gurkha Rifles, were shot dead at a checkpoint in Nahr-e Saraj. Their families have been informed.
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 latest deaths take the total number of UK service members to have died 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 were killed.
Cpl Day, who served with 3 Medical Regiment, and Cpl O'Connor, of 40 Commando, were injured on patrol with C Company in Nahr-e Saraj last Wednesday.
An initial review into their deaths has revealed the killings were not caused by "friendly fire".
The Ministry of Defence said an Afghan man, believed to have been a member of the Afghan Uniformed Police but who was not wearing uniform at the time, also died during the incident, leading to speculation it was the latest in a series of "green-on-blue" attacks in Afghanistan - where Afghans turn on their ISAF partners.
The recent spate has sparked increasing concerns of "insider attacks" on coalition troops.