KABUL, Afghanistan - A suicide bomber rammed his car into a NATO convoy in Kabul on Monday, killing three civilians and wounding at least a dozen people, including some soldiers, officials said. Clashes and an airstrike in the south killed 25 militants and eight civilians held hostage by insurgents.

Another bomb attack against a NATO convoy in the country's northwest killed one soldier and wounded several other people, including civilians. A Canadian soldier was reported killed and another seriously wounded in a skirmish with insurgents in southern Kandahar province.

The Kabul suicide bomber targeted a NATO convoy on the main road in the city's eastern outskirts, killing three civilians and wounding 12, said Ayub Salangi, the provincial police chief. The blast also wounded NATO soldiers, NATO's press office in Kabul said, but didn't give a number.

A witness who was traveling ahead of the convoy said the troops were British.

"I turned my head and saw a big burst of fire next to my car," said Ahmed Shakeb, 22. "I saw that the convoy was British."

Taliban spokesman Zabiullah Mujahed claimed responsibility for the attack, saying a man named Aminullah from eastern Khost province blew himself up. Mujahed's claim could not be independently verified.

The U.S.-led coalition, meanwhile, said militants ambushed coalition and Afghan troops Sunday on a road in the southern province of Uruzgan, triggering gunbattles during which militants moved into a compound and took 11 civilians hostage.

"Coalition troops called in close-air support to engage the militants hiding in the structure. They did not have knowledge of noncombatants in the buildings at that time," the statement said.

As a result, eight civilians were killed and three were wounded, the coalition said. The wounded civilians were taken to a coalition base for treatment.

Juma Gul Himat, the provincial police chief, said six civilians -- one child and five men -- were killed and three others were wounded in the strike. He could not immediately explain why the coalition said eight civilians were killed.

Himat blamed the Taliban fighters for using homes for cover during the clash, thus putting civilians in danger. The coalition regularly accuses militants of commandeering civilian homes to stage attacks on foreign and Afghan troops.

President Hamid Karzai and other Afghan officials have pleaded with the coalition to avoid civilian casualties, which threaten to undermine support for the government. Karzai on Sunday urged the U.S.-led coalition and NATO to go after militant sanctuaries in Pakistan rather than bomb Afghan villages.

"The struggle against terrorism is not in the villages of Afghanistan," Karzai said. "The only result of the use of airstrikes is the killing of civilians. This is not the way to wage the fight against terrorism."

More than 3,000 people -- mostly militants -- have died in insurgency-related violence this year, according to an Associated Press tally of figures from Western and Afghan officials.

In the northwestern province of Faryab on Monday, a bomb attack killed a Latvian solider and wounded three, that country's Defense Ministry said. Earlier, provincial police chief Khalil Andarabi said the attack wounded 14 people, including two foreign soldiers and 12 civilians.

Canada's government said one of its soldiers was killed Monday and another suffered serious wounds during a firefight begun when insurgents attacked a remote outpost in Panjwaii district of Kandahar province.

In other reported violence, militants ambushed a convoy of vehicles belonging to a demining company in the southern Zabul province Monday, killing two Afghan guards and wounding seven others, said Jalani Khan, a police official. Afghanistan is one of the world's most heavily mined countries after decades of war.

The attacks come at a time of an increased insurgent activity throughout the country. The number of insurgent attacks in the first six months of 2008 were over 50 percent higher compared to the same period last year, according to an Afghan security group that advises foreign aid agencies.