Six Nato service members were killed in an insurgent attack in southern Afghanistan, the international alliance has said in a statement.
Nato did not give further details, in keeping with a policy of waiting for the alliance's individual countries to identify their casualties.
Fighting has increased in southern Afghanistan as a surge of US troops poured into Helmand and Kandahar provinces this year in an attempt to push the Taliban out of their traditional strongholds.
More than 670 international troops have been killed so far this year, well above the 502 killed in the whole of 2009.
Also on Sunday, Nato said a joint Nato-Afghan force killed a Taliban leader and captured a key member of another militant group in the east.
The Taliban leader was involved in weapons smuggling and attacks in eastern Wardak province, according to a statement. Nato identified him only by his first name, Fedahi.
Two men threatened the troops as they entered a compound on Saturday night where they had heard Fedahi was staying. They shot and killed both men and one was later identified as Fedahi, the statement said. The coalition statement said no civilians were harmed in the operation.
In a separate raid in eastern Khost province on Saturday night, Nato and Afghan troops captured a leader for the Haqqani network, a Pakistan-based Taliban faction closely tied to al Qaida.
The troops captured the targeted militant in a compound in Terayzai district, according to a statement. The detainee, it said, has conducted bomb attacks and ambushes against Afghan and coalition troops.