The incident happened in the tribal district of Kurram where the vehicles carrying Shiite Muslims were targeted, the official sources told Xinhua on condition of anonymity.

The passengers were on the way to the Parachinar area of the district, from the country's east Punjab province when they were attacked, Xinhua news agency reported.

The killed and injured included women and kids, the sources said. The injured people have been shifted to a nearby hospital.

President Asif Ali Zardari has condemned the attack and directed the arrest of the perpetrators of the attack at the earliest.