Pakistani police say gunmen have killed 43 people in an attack on the country's Shiite minority.

Provincial police chief Ghulam Haider Jamali says several others were wounded in Wednesday's attack on a bus in the southern port city of Karachi.

He says the bus was en route to a place of worship for Ismaili Shiite Muslims when gunmen boarded it and sprayed the passengers with bullets. No one has claimed responsibility.

The Taliban and other Sunni Muslim extremist groups, which view Shiites as apostates, have long had a presence in Karachi and have targeted Shiites in the past.