Suicide bomber kills six in northwest Pakistan

MIRANSHAH, Pakistan (Reuters) - A suicide bomber rammed an explosive-laden car into a Pakistani security force checkpost in the North Waziristan tribal region on Friday, killing six men, a security official said.

The attack occurred near Mir Ali, a town known as a sanctuary for al Qaeda militants. A senior al Qaeda leader, Abu Laith al-Libi, was killed in a missile attack in the area, apparently fired by a U.S. drone this week.

"Two Frontier Corps and four policemen were killed," said a security official, referring to a paramilitary force.

A military spokesman confirmed the attack on the joint paramilitary-police post but said he had reports of only three dead.

Violence has intensified in northwest Pakistan in recent weeks with militants attacking security forces, who have mounted counter-attacks in response.

Many al Qaeda members and Taliban militants took refuge in semi-autonomous tribal lands on the Pakistani side of the border after U.S.-led forces ousted the Taliban in Afghanistan in 2001.

Increasingly, so-called Pakistani Taliban have been mounting attacks in towns and cities, many of them on security forces and other government targets.

In a separate incident, a roadside blast targeted a military convoy in the neighboring South Waziristan region, wounding two soldiers, a military spokesman said.

(Reporting by Haji Mujtaba; Editing by Robert Birsel and Sanjeev Miglani)