A suicide car bomber killed a policeman and a bystander in a massive explosion near the police chief's office in the southwestern Pakistani city of Quetta on Thursday, an officer said.
The attacker detonated his bomb-packed car in a parking lot opposite the Balochistan police chief's building and near other government offices in northern Quetta, said the police officer, who spoke on condition of anonymity as he was unauthorized to speak to the media.
The blast also killed a policeman directing traffic in the street and a passer-by, said Abdul Wahid Qazi, a senior police officer.
There was no immediate claim of responsibility for the attack. It came following recent police arrests of Taliban-linked militants operating in and around Quetta, a city near the Afghan border that boasts a large Afghan refugee population.
It was unclear if the attack was related to Monday's air raid on a religious school in the northwestern Bajur district, which killed 80 suspected militants and prompted calls by pro-Taliban tribesmen to launch suicide attacks against Pakistani forces.