The Pakistani police say a suicide bomber blew himself up outside a mosque in the city of Rawalpindi, next to the capital of Islamabad, killing five people.

Police officer Raja Abdul Rasheed says the Friday evening explosion targeted the mosque affiliated with Shiite Muslims. The minority sect has often been targeted by Sunni extremists who do not view Shiites as true Muslims.

Rasheed says the explosion also wounded 16 people. He said authorities believe the bomber tried to go into the mosque. When he was stopped at the entrance, he blew himself up outside.

There was no immediate claim of responsibility for the attack.

The blast happened in a narrow, congested area of Rawalpindi, which police said hampered rescue efforts.