Two soldiers from NATO's International Security Assistance Force (ISAF) were killed in a bomb explosion in eastern Afghanistan, the alliance said on Saturday.
NATO did not release the nationalities of the soldiers, but the fresh incident took the number of foreign troops killed in the war so far this year to 551-- the deadliest on record.
"Two ISAF service members died following an improvised explosive device (IED) attack in eastern Afghanistan on Friday," said a NATO press statement.
Home made bombs cause the majority of casualties among foreign and Afghan troops fighting the Taliban.
The United States and NATO allies have increased the number of foreign troops fighting a nine-year Taliban insurgency to more than 152,000.
US-led forces have stepped up attacks on insurgents since the spring as part of a new strategy aiming to root out Taliban militants before drawing down the military presence next year.