(CNN) -- Blasts targeting two mosques in northwestern Pakistan on Friday have left 15 people dead and others injured, a police official said.
The incident occurred in the village of Baz Dera in Khyber Pakhtunkhwa province's Malakand district, according to Amjad Ali, Malakand's deputy commissioner of police.
One of the explosions was caused by a time bomb planted in one of the mosques, officials said.
Worshipers were leaving a mosque after Friday prayers when the blasts took place, and some people were buried in the rubble, a tribal police official and a local intelligence official said.
Pakistan has been engulfed in political turmoil for years. Militant groups backing insurgents across the border in Afghanistan have a strong presence in Pakistan.
There had been frequent deadly attacks, by groups like the Pakistani Taliban, on people campaigning for the recent national elections.
Those elections, conducted last weekend, left Nawaz Sharif, the former prime minister whose government was overthrown by a military coup more than a decade ago, apparently back on top in Pakistan, according to unofficial results.
CNN's Joe Sterling contributed to this report.