Three British soldiers have been killed in southern Afghanistan as a result of an "enemy explosion" while a fourth died after suffering wounds from enemy fire, Britain's Ministry of Defence said.
The unidentified trio of soldiers died after an escort operation in the Gereshk district of Helmand province, southern Afghanistan, where the Taliban militia has been waging a bloody insurgency.
A response helicopter was called out, but the soldiers were pronounced dead by military doctors on Wednesday.
The fourth, a Royal Marine who was also not named, died in a military hospital in the central English city of Birmingham after coming under enemy fire while on a patrol in Sangin, also in Helmand on Monday.
He was taken to a medical facility in Kandahar, southern Afghanistan, and then on to Selly Oak Hospital in Birmingham, where he died.
"It is with great sadness that the Ministry of Defence has to announce the deaths of three soldiers from 1st Battalion The Rifles," the ministry said.
A British military spokeswoman, Commander Paula Rowe, said the Royal Marine's death was "a tragedy and his loss will be felt deeply by his family, friends and all those who served alongside him."
The deaths bring to 12 the total number of British soldiers killed in Afghanistan this year and 149 since the US-led invasion of the country in late 2001.