Nato aircraft attacked the Taliban in southern Afghanistan and killed 16 militants and 13 civilians, Afghan police said today.
Nato denied causing civilian casualties during the attack in Garmser district of Helmand province last night.
The assault came hours after a separate incident in which Nato said its troops and Afghan forces killed up to 150 insurgents infiltrating from Pakistan.
Last year was the bloodiest in Afghanistan since US-led forces overthrew the Taliban in 2001, but the violence fell off at the end of the year.
A Nato spokesman in Brussels said this week poor communications between Nato and Afghan authorities were to blame for the killing of 31 civilians last October by alliance warplanes during a battle with insurgents in Kandahar province.
In the first big clash of this year, Nato said up to 150 insurgents were killed in a series of air and artillery strikes in the southeastern province of Paktika late on Wednesday after the rebels slipped over the border from Pakistan.
Afghan anger over the infiltration of Taliban from Pakistan has damaged relations between the neighbours, both important US allies in the war on terrorism.