New Delhi, Dec. 23 -- Five Pakistani police personnel were killed on Tuesday after their vehicle was ambushed with explosives and gunfire in the country's northwest. The attack took place in Khyber Pakhtunkhwa, even as separatist and Islamist militant groups separately claimed a series of deadly assaults on Pakistani security forces in Balochistan and Sindh.

Provincial Pakistani police said the officers were travelling in a van in Karak district when the vehicle was first struck by an improvised explosive device, after which attackers opened fire.

The blast and shooting killed four police officers and the driver, officials said. No group immediately claimed responsibility for the attack.

The district, which lies in Khyber Pakhtunkhwa, ...