It was one of the deadliest attacks against foreign troops in recent weeks.
The latest deaths happened in the eastern province of Nangarhar, on the border with Pakistan. A bomb was remotely detonated to hit a convoy in Bati Kot district.
The nationality of the victims has not been announced. Most foreign troops deployed in the east are Americans.
In Kabul, a suicide bomber killed two civilians this morning in an attack on a convoy, and in Kandahar in the south a bomb which appeared to target the city's mayor killed a passerby.
Yesterday, two NATO soldiers, one in the east and one in the south, were killed in two separate attacks by the insurgents.
