A roadside bomb exploded Wednesday as a vehicle carrying security forces passed through a former stronghold of local militiamen in northwestern Pakistan, killing four, police said.
The attack occurred in Bajur, a district on Pakistan’s border with Afghanistan. The area served as a base for the Pakistani Taliban until a few years ago, when the army said it had cleared the region of insurgents, but violence has continued there.
No one has yet claimed responsibility for the most recent attack.
Police official Abdul Samad Khan said two policemen and two soldiers were killed in the attack. He said a search operation was launched in the region to find those responsible.
Khan declined to speculate on who might be behind the attack, but suspicions fell on the Pakistani Taliban, which has been emboldened by the Taliban’s return to power in neighboring Afghanistan, where thousands of Pakistani militiamen are believed to still be hiding.
Pakistan and Afghanistan share an internationally recognized 2,400-kilometer (1,500-mile) border, the so-called Durand Line, which was drawn in the 19th century when the British dominated South Asia. Kabul has never recognized that border.