PESHAWAR, Pakistan, August 28, 2009 (AFP) - A suicide bomber killed at least 21 policemen in Pakistan's northwestern tribal region on Thursday, after a US strike from a drone aircraft killed eight Taliban militants, officials said.

The suicide attack took place in the Khyber tribal region near the Afghan border just as the policemen were gathering to break their Ramadan fast.

"It was a suicide attack, which killed at least 21 policemen and wounded 15 others," top local administration official Tariq Hayat told AFP.

He said the attacker blew himself up in the police barracks in the border town of Torkham.

A senior administration official, Rehan Gul Khattak, told AFP: "The authorities have found the head of the bomber at the site."

A local administration official, Naeem Afridi, said he feared the death toll would rise. "Vehicles of the local administration are shifting the injured and dead bodies to a local hospital," he added.

The attack came hours after a US missile strike in the South Waziristan tribal region killed eight militants.

The US strike "targeted a Taliban compound in Kaniguram village of South Waziristan, killing eight militants and wounding six others," a senior security official told AFP.

Another official confirmed the casualties and said that the drone fired two missiles.

"Militants were using the compound of local tribesman Azam Khan Mehsud for their activities in the area," he said.

"Nationalities of all the militants killed... were not immediately known but some were Uzbek nationals."

He added that the village contained hideouts belonging to fighters loyal to slain Pakistani Taliban chief Baitullah Mehsud, who was killed in a US drone attack on August 5. His death was confirmed by Taliban commanders on Tuesday.

The US military does not, as a rule, confirm drone attacks, but its armed forces and the Central Intelligence Agency are the only forces that deploy drones in the region.

More than 2,000 people have been killed in a series of bomb blasts and suicide attacks in the country during the past two years.

Pakistan's northwest and tribal areas have been wracked by violence since hundreds of Taliban and Al-Qaeda fighters sought refuge there after the US-led invasion of Afghanistan in 2001.

Pakistan in April launched a military offensive against the Taliban in the northwest, targeting the rebels in the districts of Swat, Buner and Lower Dir after militants advanced closer to the capital Islamabad.

Pakistan says more than 1,930 militants and over 170 security personnel have been killed in the offensive, but the death tolls are impossible to verify independently.

The military last month claimed to have cleared the Swat area of Taliban and has now turned to the tribal belt, heartland of Pakistani umbrella organization Tehreek-e-Taliban Pakistan (TTP), which is allegedly linked to Al-Qaeda.

But skirmishes still continue in Swat and Buner, raising fears that the Taliban are regrouping in the mountains.