PESHAWAR, Pakistan – At least 64 people were killed in blasts at two Sunni mosques in Pakistan’s restive northwest on Friday.

In the first attack, in a mosque outside the city of Peshawar, a teenage suicide bomber detonated his explosives during Friday afternoon prayers, causing the roof to collapse on hundreds of worshippers and killing at least 60 people, government and police officials said. It was the largest bombing in Pakistan since September, when a blast killed more than 60 people in the southwestern city of Quetta.

The second attack occurred during evening prayers at a mosque a few miles away. Militants hurled three grenades and set off a bomb, police said.

The Pakistani television network GEO reported the Taliban asserted responsibility for the first bombing, in the town of Darra Adam Khel.

A tribal elder who had organized residents against the Taliban lived in a guesthouse adjacent to the mosque and might have been the target, authorities said. Residents said he had recently moved to Dubai.

In Badabher, where the second bombing took place, residents had organized a peace committee to patrol against militants.

The sites of both attacks border the tribal areas where the Pakistani military has waged offensives in recent years against homegrown militants.