“A suicide car bomb exploded at the gate of Waberi district police station. So far we know four people died,” he said.
Witnesses described bodies lying on the ground, ruined cars and damage to the police station. There was no immediate claim of responsibility for the attack.
This is the third attack to hit the capital in three days.
On Tuesday, at least 10 people were killed in a car bomb attack on a government building.
At least 15 people were killed after a suicide car bomber posing as a milk delivery van detonated at a district headquarters on Wednesday.