The attack took place during prayers in the Darra Adam Khel area, near Pakistan's tribal regions

Hours later, grenades thrown into a second mosque, near Peshawar, killed at least two people, police said.

It was not immediately clear who carried out the attacks, the latest in a series of mosque and shrine bombings.

The Pakistani Taliban have claimed responsibility for such attacks in the past and have been particularly active in recent years in and around Peshawar.

In the later attack, unknown assailants threw hand grenades into a mosque during evening prayers in the village of Sulemankhel, about 7km (4.5 miles) north of Peshawar, police said.

At least two people were killed and more than 20 injured.