The Western military on Sunday suffered its most lethal day in a month in Afghanistan, with seven troops killed in the south and east, the NATO force said.
Meanwhile, the Afghan government said an Afghan diplomat kidnapped by insurgents two years ago in Pakistan's tribal areas had been freed a day earlier. A brief statement from the presidential palace credited his release on "persistent efforts" on the part of the Pakistani and Afghan governments but gave no details.
The envoy, Abdul Khaliq Farahi, was released in eastern Afghanistan, across the border from where he had been seized. Insurgents based in Pakistan's tribal areas are able to move back and forth across the frontier with little impediment.
Fighting generally eases as the winter sets in, because many Taliban and other fighters spend the season in Pakistan, and snow in the high mountain passes makes it difficult to move between the two countries. This year, however, clashes have persisted even as the weather has begun to turn cold.
The Taliban and the main insurgent group active in Afghanistan's east, the Haqqani network, appear determined to show they can fight on in the face of a concerted NATO campaign targeting midlevel field commanders. Hundreds have been killed in targeted strikes over the last several months, military officials have said.
The North Atlantic Treaty Organization force did not disclose the nationalities or other details about the five fatalities in the east and the two in the south. Large numbers of U.S. forces serve in both regions, particularly the south.
Americans make up two-thirds of the 150,000 Western troops in Afghanistan, suffering a proportionate number of casualties. Before Sunday's deaths, American fatalities made up 438 of the 639 NATO forces killed this year, according to the website icasualties.org.
The 2010 total is already the highest yearly toll of the war, which is in its 10th year. Sunday's was the highest single-day fatality total since Oct. 14, when eight troops were killed.
Afghan civilians have been dying in record numbers as well. Three civilians were killed in explosions Sunday in southern Afghanistan that also killed three Afghan policemen.
The NATO force also said an Afghan child in Kandahar province was accidentally killed Sunday, apparently by Western artillery fire. Another child was injured in the incident, which occurred after a Western patrol came under attack in volatile Zhari district, NATO's International Security Assistance Force said in a statement.
Though attention has been focused on a major American offensive on the outskirts of Kandahar city, the hub of the south, the east also has seen persistent insurgent attacks.
In the eastern province of Nangarhar, where a squad of gunmen and suicide bombers had attacked a large NATO air base Saturday, insurgents on Sunday set a dozen NATO fuel tankers ablaze, provincial officials said.