KABUL - Taliban militants ambushed U.S.-led coalition and Afghan forces escorting supply trucks in southern Afghanistan, sparking a 10-hour battle the coalition said killed an estimated two dozen militants, though villagers said Monday seven civilians also died.

In the north, a suicide bomber targeted foreigners in a four-wheel drive vehicle Monday, killing two Afghan civilians and wounding two others, officials said.

The southern violence began Sunday when an Afghan police and coalition convoy hit two roadside bombs and was ambushed by Taliban fighters while escorting 24 supply trucks in Helmand province, a coalition statement said Monday. The blast killed one Afghan truck driver and wounded three coalition soldiers, it said.

Militants then launched rocket-propelled grenades and opened up with small-arms fire and the ensuing 10-hour clash and air strikes killed "an estimated two dozen enemy fighters,'' the coalition statement said.

The coalition said "one enemy fighting position'' was destroyed and "no Afghan civilian injuries were reported.''

But Abdul Qudus, a villager from Helmand's Gereshk district, said by phone that air strikes hit a civilian area.

"They came and bombarded the houses of innocent people. Three houses were destroyed.''

"Seven people -- including women and children -- were killed and between 10 and 15 were wounded,'' Qudus said.

"Villagers are still searching for five missing people.''

Another villager, Abdul Wahid, said the air strikes hit 16 ki;ometres away from the convoy ambush site on the main highway.

There was no way to verify the claims of either the coalition or the villagers at the remote battle site. Taliban fighters often seek cover in civilian homes, where they fire on U.S. and NATO forces, leading those homes to be targeted.

Civilian deaths have been a point of contention between the government of President Hamid Karzai and U.S. and NATO forces. Though the foreign troops say they do everything they can to avoid civilian casualties, an estimated 135 civilians have been killed this year due to U.S. or NATO military action, by an Associated Press count based on numbers from U.S, Afghan and UN officials.

In northern Kunduz, a suicide bomber targeted foreigners in a four-wheel drive vehicle but they were unhurt in the blast, said Kunduz provincial police chief Gen. Ayub Salangi. Two civilians in a nearby car were killed, he said.

Provincial health department director Azizullah Safer said two other civilians were wounded.

Northern Afghanistan is usually relatively quiet but Kunduz has seen a spate of violence in recent months. The last suicide attack nine days ago killed three German soldiers and seven civilians in a busy market.

Violence has picked up sharply in Afghanistan the last several weeks. More than 1,800 people have been killed in insurgency-related violence this year, by the AP count.