At least six people have been killed in Pakistan's northwest after a suicide bomber attacked the home of a provincial minister during mourning for his son's death two days earlier.

Four police officers were among the dead on Monday, while 20 other people were wounded by the blast in the town of Pabbi, 25km from provincial capital Peshawar.

Witnesses said the bomber appeared to be a young boy.

Mian Iftikhar Hussain, the information minister of Khyber Pukhtoon Khawa Province, was the apparent target of the bombing, although escaped unharmed. Hussain's son was shot dead by armed men on Saturday in an attack blamed on the Pakistani Taliban, and he was receiving condolences at his house when the bomber struck.

A videotape recently surfacedof Fazlullah, the leader of the Swat Taliban who was thought to be dead, calling on suicide bombers to attack Pakistani government officials and the military.

Swat fighting

Fazlullah had previously led a two-year campaign to take over the Swat Valley area, before Pakistani forces launched a major offensive in April 2009 to try to drive him and his supporters out.

Pakistani officials claimed Fazlullah had died in fighting near the Afghan-Pakistan border last May.

After local media obtained the new Fazlullah tape on Friday, Iftikhar Hussain had told Al Jazeera that the video showed the military was succeeding in restricting Taliban's fighters' efforts in the area.

"They have become cowards and are now issuing such videos to overcome their defeat," he said.

For two years the Taliban paralysed much of the valley by promoting its repressive brand of sharia.

Many of the estimated two million people who fled have now returned to their homes in and around Swatand are trying to rebuild their lives, but skirmishes, threats and tensions have remained.

Pakistan's northwestern region has become a stronghold for both al-Qaeda and Taliban fighters who fled Afghanistan following the US-led invasion that toppled the Taliban government in 2001.