ISLAMABAD, Nov. 19 (Xinhua) -- At least four people were killed in a missile attack in northwestern Pakistan on Wednesday, private TV channel Geo reported.

    Some unknown militants fired a missile in Andi Khel area of Frontier Region of Bannu district in North West Frontier Province, killing four persons and injuring several others, said the report.

    The injured were shifted to a nearby hospital for treatment. Security forces cordoned off the area after the incident.

    No group has claimed responsibility for the attack.

    However, the DAWN NEWS TV channel said the missile attack was launched from a United States drone.

    Pakistan's tribal areas have witnessed cross-border missile attacks conducted by suspected U.S. drones. Pakistani government has repeatedly protested against missile strikes in its territory and demanded a halt to such attacks.