a local government official has told BBC Urdu. The attackers opened fire on police guarding the construction site of a multi-billion rupee dam in the Ziarat district, Deputy Commissioner Abdul Quddus Achakzai said. Two senior officers are among those killed, and a search operation is under way to find missing personnel, he added. No group has claimed responsibility for the attack. Balochistan officials said security forces had killed 15 members of the Pakistani Taliban (TPP) in response, as part of a "clearance operation" in Ziarat.

Protests against the attack on police have been taking place along a national highway near the site of the incident. Pakistan's Interior Minister Mohsin Naqvi condemned the attack, saying the killed officers were "the pride of our nation". Officials say they were guarding the construction site of the Mangi Dam, which is being built to help overcome a water shortage facing Balochistan's capital city of Quetta. The province, which borders Afghanistan and Iran, has seen unrest for decades, as local militant groups demand greater autonomy from the Pakistani government. In May, local officials said the Balochistan Liberation Army separatist group was behind an attack on a train transporting military personnel, which killed 20. The area has also seen cross-border attacks. Last week, Afghanistan's Taliban regime said it had carried out strikes in the region, with Pakistan's military saying it had shot down four drones. (BBC)