A total of six NATO soldiers were killed in attacks in Afghanistan on Wednesday, four of them in a bomb explosion in the insurgent-hit south of the country, the alliance said.
NATO's International Security Assistance Force (ISAF) gave no further details of the four soldiers' deaths in the blast, saying it was a matter of policy not to identify the nationalities of casualties.
The coalition had earlier announced that a soldier was killed in another bomb attack, as military deaths hit new record highs since the war began in 2001.
The sixth soldier died fighting rebels in eastern Afghanistan, the force said.
Improvised bombs also known as IEDs are the weapons of choice for the Taliban and other insurgents fighting heavily-armed international forces and Afghan troops.
The cheap and easy-to-make devices cause the bulk of the military deaths and are hard to detect as most roads in Afghanistan are unpaved.
There are more than 150,000 foreign troops, mainly Americans, fighting Taliban guerrillas trying to regain power since they were ousted in a US-led invasion late 2001.
So far, at least 581 foreign soldiers have been killed this year, the deadliest year on record, eclipsing the previous record of 521 in 2009.
The AFP tally is based on a count by the independent website icasualties.org which tracks military deaths in Afghanistan and Iraq.
The surge in military deaths has been parallel to increased military operations by the coalition force and their Afghan partners in some of the most dangerous parts of the country where the Taliban have a strong presence.
About 40,000 US and NATO extra troops were deployed this year under the White House's new war strategy for Afghanistan.