Suicide bomber kills four in Afghan capital

KABUL (Reuters) - A suicide car-bomber attacked a military-civilian convoy on Saturday in the Afghan capital, killing four civilians, police and NATO-led forces said, in the third such attack on international forces in two days.

The suicide attacker drove a car packed with explosives at vehicles carrying both foreign troops and civilians on the western outskirts of Kabul, a senior police official said.

He said five people were wounded, including a foreign soldier.

"Right now we think it may have been a private convoy of private contractors," a spokesman for the NATO-led International Security Assistance Force (ISAF) said, adding that ISAF troops might have been attached to the convoy to provide security.

One soldier could have been among the killed or wounded, he added, but he could not confirm this yet.

Taliban guerrillas have been waging an insurgency against the Afghan government and its foreign allies since U.S.-led forces evicted the Talibs from power in 2001 for refusing to give up their ally, al Qaeda leader Osama bin Laden.

But suicide bombings are a relatively recent phenomenon in Afghanistan. In the past two years, the Taliban and their al Qaeda allies have stepped up such attacks, though there had not been a suicide bombing in the capital for many weeks.

On Friday, a suicide car-bomber attacked foreign troops in central Afghanistan, killing 10 people, including five children and a Dutch soldier.

Later in the day, a second suicide bomber on foot attacked a foreign troop convoy in the southern Kandahar city, wounding at least five civilians, a police official said.

Afghan interior ministry spokesman Zemarai Bashary said authorities were investigating Saturday's suicide attack but he doubted it was part of a new, intensive campaign to disrupt security across the country.

"This is something different," he said. He did not elaborate.