With the weather warming, foreign and government forces pressed on with their largest-ever anti-Taliban offensive in the south. But the 11 NATO deaths since last weekend are a sign the insurgency remains virulent.
In Helmand province, the focus of the offensive, U.S.-led coalition and Afghan troops fought for five hours Thursday with guerrillas in the district of Sangin, a coalition statement said.
The troops "pursued fleeing Taliban fighters northward," and "more than 35 Taliban fighters were killed," the statement said.
The account could not be independently verified because of the remoteness of the area.
More than 5,000 NATO and Afghan troops are engaged in Operation Achilles, launched last month to flush militants entrenched in the northern tip of the opium-producing province.
A British soldier for NATO was killed and two soldiers were wounded in a firefight in the south on Friday, officials said.
In Zabul, a province on the Pakistani border, officials reported 35 suspected militants killed in an air strike called by U.S.-led troops on Thursday.
The violence coincided with a gathering of NATO military officials in Canada to discuss how to strengthen their efforts in Afghanistan.
NATO and U.S. leaders have made repeated calls for more resources, but have met resistance from some allies, including the French and Germans, who questioned the wisdom of deploying more combat troops and said more emphasis should be placed on reconstruction.
Returning from that meeting, Defense Secretary Robert Gates said NATO wants about 3,400 more trainers for the Afghan army and police force. U.S. officials hope European nations will meet most of that need.
The NATO-led force in the south also needs more aircraft and medical equipment as well as military trainers to bolster its spring assault against the Taliban, according to the U.S. military.
The U.S. now has about 25,000 troops in Afghanistan, including some 14,000 serving in the NATO-led force, which totals about 36,000 troops.
Separately, the coalition said American special forces and Afghan troops rescued five civilian contractors pinned down under insurgent gunfire after their helicopter made an emergency landing because of mechanical failure, the U.S.-led coalition said.
The contractors were evacuated to a nearby coalition base, where they were treated for minor injuries, the statement said.
Neither the company nor the contractors were identified.
Contractors and the military rely heavily on helicopters for transport and operations because of Afghanistan's forbidding terrain, lack of passable roads and frequent ambushes by insurgents. Dust and high altitude take a heavy toll on helicopter engines.
In February, a U.S. Army CH-47 Chinook carrying 22 U.S. service members crashed because of mechanical failure in southern Afghanistan, killing eight and injuring 14.