World Bulletin/News Desk

A remotely-controlled blast in northwestern Pakistan has killed four troops on Thursday. 

A senior military official said, on condition of anonymity, that the blast struck a patrolling vehicle in the Shabaq area of Kurram Agency, one of Pakistan's seven semi-autonomous tribal areas. 

No group has so far claimed responsibility for the attack, which is the latest in a series of ambushes and blasts, but security agencies believe Taliban militants are responsible.