KARACHI, Pakistan (AP) — Police say a car bomb has killed at least 37 people and wounded another 141 in a neighborhood dominated by Shiite Muslims in the southern Pakistan city of Karachi.

Karachi is Pakistan’s economic hub has been the site of political, sectarian and ethnic violence for years. No one has taken responsibility for the bombing, but Shiites Muslims have been increasingly targeted by Sunni militant groups.

The bomb exploded outside a Shiite mosque as people were leaving evening prayers.

A top government official, Taha Farooqi, says at least 37 people are confirmed dead and 141 more were wounded.

Initial reports suggested the bomb was rigged to a motorcycle, but a top police official Shabbir Sheikh said around 100 kilograms (220 pounds) of explosives was planted in a car.