A roadside bomb hit a Nato vehicle in southern Afghanistan, killing six soldiers and their Afghan interpreter, Nato said in a statement.
The attack happened in a volatile region of Kandahar province, Afghan police officials said.
Nato did not release the nationalities of the dead soldiers, but they are not believed to be British.
The majority of soldiers in Kandahar are Canadian.
The attack was the deadliest against foreign troops in Afghanistan since May 13, when seven troops were killed – five Americans, a Canadian and a Briton - when the Chinook helicopter they were riding in crashed in Helmand province.
Today’s attack bring to at least 102 the number of foreign soldiers that have been killed in Afghanistan this year, including at least 46 Americans, 18 Britons and 16 Canadians.
Militants yesterday battled Afghan and US-led coalition troops in three separate clashes in southern Afghanistan, leaving 20 militants and one policemen dead.
Militants attacked at least three police checkpoints in Ghazni province, and ensuing gun battles left 13 militants and one officer dead, said. Gen Ali Shah Ahmadzai, the provincial police chief.
In Zabul province, Afghan and US-led coalition forces clashed with suspected Taliban militants yesterday in Shahjoy district, leaving seven militants dead and six others wounded, said Ali Kheil, a spokesman for the province’s governor.