The blasts devastated Yakaghund town in Pakistan's northwest tribal belt on Friday, destroying government buildings, shops and burying victims under the rubble.
Local administration chief Rasool Khan said the death toll had jumped to 102, after he and other officials had earlier put the number of dead at 65.
"Some bodies were recovered from the spot and some died in hospitals overnight," he told AFP.
Another local official, Mairaj Mohammad, confirmed the higher toll and said there were 98 people receiving treatment in different hospitals. "Some of them are in critical condition," he said.
It was the deadliest attack since a massive car bomb that destroyed a market crowded with women and children in Peshawar, killing at least 125 people in October 2009.
Khan said the toll may rise further as rescue work was underway to recover victims who are feared trapped under pulverised buildings.
Pakistani Taliban claimed responsibility for Friday's blasts, saying the target was a gathering of pro-government tribal elders.
Qari Ikramullah, a spokesman for Taliban militants in the region, said in a telephone call to AFP that they were meeting in an administrator's office and planning to raise a lashkar, or tribal force, to fight the Taliban.
"We will attack such gatherings in future also," he said.
Witnesses said the huge explosions Friday damaged an administration office, shops, a jail and other buildings in the small town not far from the border with Afghanistan, where 140,000 US-led foreign troops are fighting the Taliban.
The attack sent a pall of gloom over the town. Bodies wrapped in white shrouds were being brought to a local playground for funeral prayers, an AFP reporter saw.
At least 1,000 people gathered at a nearby graveyard where workers set about digging new graves.
"The attack appears to be part of a sustained campaign to disrupt peace efforts in the region," said security analyst Imtiaz Gul, the author of a recently published book on the tribal region, "The Most Dangerous Place".
"There seems to be good coordination among forces, which are out to create instability and perpetrate violence".
The Islamic republic is on the frontline of the US war against Al-Qaeda, and the Pakistani military are bogged down fighting homegrown Taliban in the northwestern border areas.
Hugging the border with Afghanistan, where US and NATO allies are trying to end a nearly nine-year war, northwest Pakistan has suffered a wave of bombings causing mass casualties and insurgency, fanning fears about regional stability.
Pakistani leaders this week called for a landmark national conference to develop a strategy to counter the Islamist militant threat after a twin suicide attack killed 43 people at a shrine in Lahore on July 2.
Pakistani security forces have fought in the tribal belt and parts of the northwest for years, but deadly clashes are still largely a daily occurrence.