The incident occurred at a police checkpoint in Qalat, capital of Zabul province, as the Taliban ramp up their annual spring offensive launched last month against Western-backed Afghan forces.
“Around 3:00 am today a policemen opened fire on his colleagues in Zabul, killing eight of them,” Ghulam Jilani Farahi, deputy police chief of Zabul, told AFP.
“The attacker fled to the Taliban after the incident. He also stole a pick-up truck, weapons and ammunition.”
The provincial governor’s office confirmed the incident and death toll.
Taliban spokesman Qari Yousuf Ahmadi said the insurgents were behind the assault.
So-called insider attacks — when Afghan soldiers and police turn their guns on their colleagues or on international troops — have been a major problem during NATO’s long years fighting alongside Afghan forces.
The Afghan military, which was rebuilt after the fall of the Taliban regime in 2001, has struggled with the phenomenon, as well as high casualty rates and mass desertions.
In mid-February, another Afghan policeman drugged his colleagues before shooting five of them dead in Kandahar province.