Grief-stricken relatives and residents on Saturday buried the victims of a suicide bombing at a northwestern Pakistan mosque that left about 50 dead, officials and witnesses said.

A suicide bomber blew himself up during Friday prayers at the packed mosque in the northwestern tribal town of Jamrud, also leaving scores wounded in one of the bloodiest recent attacks in Pakistan.

Relatives of the dead, helped by residents, dug graves in the rugged terrain and prayed, administration official Bakhtiar Mohmand said.

"The whole town is in mourning," Mohmand said.

"There are several trucks parked near the mosque and apparently the drivers and helpers of these trucks, who stopped to offer prayers (on Friday), died in the bombing," Mohmand told AFP.

Several limbs picked out of the rubble of the mosque were also buried in a nearby graveyard.

There was no claim for the attack, but Pakistani security officials said they suspected the bombing was to avenge operations against Taliban fighters and other Islamist militants aimed at securing NATO supplies into Afghanistan.

US officials say northwest Pakistan has degenerated into a safe haven for Al-Qaeda and Taliban militants who fled the 2001 US-led invasion of Afghanistan and have regrouped to launch attacks on foreign troops across the border.

Extremists opposed to the Pakistan government's decision to side with the United States in its "war on terror" have carried out a series of bombings and other attacks that have killed nearly 1700 people in less than two years.

AFP