Photo taken on Nov. 16, 2012 shows the wreckage of a vehicle of security forces at the suicide blast site in Zhob, Pakistan's southwest province of Balochistan, on Nov. 16, 2012. At least four people including two troops were killed in a suicide blast here on Friday morning, said an officer. (Xinhua/Stringer)

A policeman inspects the suicide blast site in Zhob, Pakistan's southwest province of Balochistan, on Nov. 16, 2012. At least four people including two troops were killed in a suicide blast here on Friday morning, said an officer. (Xinhua/Stringer)