Police: Gunmen kill 43 in attack on Shiite minority in southern Pakistan

People visit a local hospital following an attack on a bus in Karachi, Pakistan, Wednesday, May 13, 2015. Gunmen killed dozens of people on Wednesday aboard a bus in southern Pakistan bound for a Shiite community center, in the latest attack targeting the religious minority, police said. (AP Photo/Fareed Khan) (The Associated Press)

Police cordon off the site of an attack by gunmen in Karachi, Pakistan, Wednesday, May 13, 2015. The attackers killed dozens of people on Wednesday aboard a bus in southern Pakistan bound for a Shiite community center, in the latest incident targeting the religious minority, police said. (AP Photo/Shakil Adil) (The Associated Press)

Pakistani paramilitary troops stand guard outside a local hospital following an attack on a bus in Karachi, Pakistan, Wednesday, May 13, 2015. Gunmen killed dozens of people on Wednesday aboard a bus in southern Pakistan bound for a Shiite community center, in the latest attack targeting the religious minority, police said. (AP Photo/Fareed Khan) (The Associated Press)

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.