Hundreds of Shiite Muslims have gathered in Karachi amid tight security for a mass funeral for those killed in a pair of bombings. At least 25 people died in Karachi on Friday when suspected militants targeted a bus carrying Shiite worshippers and then attacked a hospital treating victims of the first bomb. Paramilitary spokesman Maj. Aurang Zeb said Saturday that security forces were on maximum alert ahead of the funeral in the Malir area of the southern port city. Many businesses were observing a strike over the attacks. Karachi has a history of violence between Shiite and Sunni Muslims. A December bombing in the city killed 44 people at a Shiite procession.