Pakistani security officials say five people have been killed in a U.S. drone (unmanned aircraft) attack on a suspected militant target in Pakistan's northwest tribal region.
The officials say missiles hit a house Saturday in the North Waziristan tribal district near Afghanistan. They say two people were wounded.
It is not clear if the casualties were militants.
Many Taliban gunmen and other militants battling U.S. and NATO forces in Afghanistan are based in North Waziristan.
In the southern port city of Karachi, police say at least 19 people were wounded Saturday in an explosion near a group of Shi'ite Muslims taking part in a procession for the Islamic holy month of Muharram. There were conflicting reports as to the cause of the blast, with some saying it was a car bomb, and others saying it was caused by a firecracker.
Pakistan is mostly Sunni, and extremists from the two sects have often clashed in the country.
In other violence, Pakistani officials say militants have assassinated a tribal leader who commanded a village militia fighting Taliban militants in North Waziristan.
The officials say Gul Mohammad's beheaded body was found on a roadside in the Bajaur district. Taliban militants often attack tribal leaders considered to be pro-government in efforts to gain control in northwest Pakistan.
Some information for this report was provided by AP, AFP and Reuters.