U.S.-led coalition and NATO forces fighting insurgents in Afghanistan have killed at least 203 civilians so far this year — surpassing the 178 civilians killed in militant attacks, according to an Associated Press tally.

Insurgency attacks and military operations have surged in recent weeks, and in the past 10 days, more than 90 civilians have been killed by air strikes and artillery fire targeting Taliban insurgents, said President Hamid Karzai.

On Sunday, another civilian may have been killed when British troops opened fire in a populated area after their convoy was hit by a roadside bomb, officials and witnesses said.

Separate figures from the UN, and from an umbrella organization of Afghan and international aid groups, each show that the numbers of civilians killed by international forces is approximately equal to those killed by insurgents.

After a seething speech by Karzai on Saturday, in which he accused NATO and U.S. forces of viewing Afghan lives as "cheap," NATO conceded that it had to "do better." U.S. military spokesman Maj. Chris Belcher suggested that some civilians reportedly killed by foreign forces may in fact have been killed by insurgents.

"One of the problems is sometimes determining who exactly caused the casualties. It's not always clear if a civilian casualty is caused by an extremist or coalition forces," Belcher said.

Accurate figures for civilian death tolls are hard to come by in Afghanistan, where militants often wear civilian dress and seek shelter in villagers' homes. Furthermore, after a quarter of a century of civil war and conflict, it is not unusual for Afghans to have weapons in their homes.

Much of the violence takes place in remote areas that are too far or too dangerous for independent observers or journalists to reach for verification of the reports.

The AP count of civilian casualties is based on reports from Afghan and foreign officials and witnesses through Saturday. Of the 399 civilian deaths so far this year, 18 civilians were killed in crossfire between Taliban militants and foreign forces.

The U.S. and NATO did not have civilian casualty figures. The UN Assistance Mission in Afghanistan has counted 213 civilians killed by insurgents in the first five months of this year, compared to 207 killed by Afghan and international forces.

ACBAR, the Agency Co-ordinating Body for Afghan Relief, has counted 230 civilians killed in U.S. and NATO operations, basing its figure on reports from the Afghan Independent Human Rights Commission, Afghan NGO Security Office and the UN.

The number of civilians killed in militant attacks was approximately the same as those killed by foreign forces according to ACBAR's latest figures from about a month ago, said Anja de Beer, director of ACBAR.