The army said its forces killed five anti-government fighters and destroyed three bases in its latest offensive in the northwestern tribal region of Khyber, bordering Afghanistan.

Suicide bomb

"It's an assault against terrorists, anti-social and anti-state elements and it will continue until the region is cleared of them," Tariq Hayat Khan, a government officer, told Reuters news agency.

The offensive in Khyber came less than a week after a suicide bomber killed 22 Pakistani border guards in an attack at the main crossing point into Afghanistan.

The August 27 attack was the first major operation since Baitullah Mehsud, the Pakistani Taliban chief, was killed in a US missile strike in early August.

Security officials have been expecting reprisals following his death.

The US sees northwestern Pakistan as another front in the Afghan war, and Washington has been urging Pakistan to crack down on the Taliban in its territory.