QUETTA Gunmen riding a motorbike sprayed a police vehicle with bullets in southwest Pakistan on Wednesday, killing four officers, police said.

The incident took place on a main road on the outskirts of Quetta.

Unidentified gunmen riding a motorbike opened fire on a police vehicle while it was on its way to police training school, killing four police officers, senior police official Humayun Jogezai told AFP.

Jogezai said no one had claimed responsibility for the attack, in which one high-ranking police official also sustained serious injuries.