PESHAWAR: Gunmen armed with grenades killed at least three Shias and wounded six others on Monday after ambushing a bus in a Pakistani tribal region plagued by sectarian violence, officials said.

The incident took place in Charkhel village of Parachinar.

“Gunmen attacked a passenger bus carrying Shias with hand grenades and firearms, killing three Shias and wounding six others,” a local administration official told AFP on condition of anonymity.

The bus came under attack while en route to Peshawar, the main city in the northwest, he said, adding that nobody has so far claimed responsibility.

A security official in the area confirmed the attack and casualties.

Parachinar is the main town in Kurram district, part of the semi-autonomous tribal belt where US drone strikes target Taliban and al Qaeda-linked militants in what Washington considers the world's largest international terror hub.