British Prime Minister David Cameron made an unannounced trip to Afghanistan to demonstrate the growing stability in the country and to see how troops are helping to train up the Afghan security services. –AFP Photo

KABUL: British Prime Minister David Cameron made a surprise trip to Afghanistan Tuesday and urged an investigation into the death of a British soldier in a friendly fire incident in the country’s south.

The British Defense Ministry has said a British soldier who died in southern Afghanistan on Sunday may have been killed by supporting fire from a US aircraft.

He was shot while on patrol in Nad Ali district of Helmand province. He was the 346th death among British forces and civilian defense workers in Afghanistan since 2002.

‘‘Well, it’s absolutely tragic when incidents like this happen and my heart goes out to the family concerned — to lose the loved one and to lose the loved one in this way is obviously a terrible thing,’’ he said in the southern Helmand province. ‘‘There’ll have to be a proper investigation to find out what happened and how this went wrong.’’

At the Nato summit in Lisbon last month, Cameron said British troops will quit their combat role in Afghanistan by 2015.