Pakistani medical staff tend to a man injured in a suicide bombing at a local hospital in Bannu, Pakistan, Friday. (AP)

PESHAWAR, Pakistan (AFP) — Investigators sifted through rubble Saturday after a suicide car bomber detonated his explosives-filled vehicle in a crowd watching a volleyball game in northwest Pakistan, killing at least 88.

Friday's bombing marked a bloody start to 2010 for Pakistan, which has seen a surge in attacks blamed on the Taliban in recent months as Islamist fighters avenge military operations aimed at crushing their northwest strongholds.

The huge blast was Pakistan's deadliest in more than two months, triggering the collapse of more than 20 houses, some with families inside, in a village bordering a Taliban stronghold, officials said. The attack was condemned by Britain and the United States, with Secretary of State Hillary Clinton vowing the US would continue supporting Pakistani people ''in their efforts to chart their own future free from fear and intimidation.''

The bomber detonated his explosives-packed vehicle as fans gathered at a volleyball court to watch two local sides face off in the village of Shah Hasan Khan, in Bannu district, bordering Taliban stronghold South Waziristan.

''The villagers were watching the match between the two village teams when the bomber drove his double-cabin pick-up vehicle into them and blew it up,'' district police chief Mohammad Ayub Khan told AFP. ''The death toll has risen to 88 and 37 others were wounded,'' Khan said.

Six children and five paramilitary soldiers were among the dead, he added. The tournament was organised by the local peace committee, who had supported a government operation to expel militants from the area, Khan said. It was the highest death toll from a suspected militant strike since a massive car bomb on October 28 killed 125 people in a crowded market in the northwestern provincial capital Peshawar.

Ramzan Bittani, a 33-year-old driver, told AFP by telephone from a local hospital that he had left the match to take a call. ''As I was listening, I saw a huge blue and white flash followed by an ear-piercing blast. When I was able to figure out what had happened, I saw bodies and smoke all around. My hand was fractured,'' he said.