At least six people were killed and five others injured on Friday when a bus was targeted with a roadside bomb in Pakistan's troubled Mohmand tribal region, the latest in a string of attacks that have shaken the country.
The improvised explosive device went off as the bus was passing by Lakaro sub-division of Mohmand tribal agency in the country's northwest, officials of the local administration said.
It could not immediately be ascertained why the bus, which was carrying civilians, was targeted.
In the past few weeks, militants and suicide bombers have targeted several security facilities, including the army's fortified headquarters in Rawalpindi, the Federal Investigation Agency office and police training centres in Lahore and the Inter State Intelligence's provincial headquarters in Peshawar.
Dozens have died in these attacks.The Taliban have claimed responsibility for many of the attacks on the security forces, which began after the army launched operations against militants in South Waziristan tribal region in October.