A serial killer may have been behind the rape and murder of young girl in Pakistan whose killing sparked deadly clashes, an official said Saturday.Rana Sanaullah, the home minister for Punjab province, said DNA testing has linked the killing to at least five other cases of child abuse and murder in the city of Kasur. Police have detained eight suspects, including two relatives of the girl.The eight-year-old girl went missing last week while heading to a nearby home for Quranic studies. The discovery of her body, which was found in a garbage bin Tuesday, ignited clashes between residents and police that killed two people and wounded three others.The residents say the authorities were slow to respond to the girl’s disappearance, charges denied by police.The city appeared calm but tense on Saturday after three days of clashes. Businesses reopened, but police and paramilitary troops were still out in force and guarding government buildings.Sanaullah expressed hope for a breakthrough, saying new footage from surveillance cameras showed a man with a thin beard, who resembles police sketches of the suspect, walking near her house. He said the head of the investigation was replaced by another seasoned officer following complaints by the victim’s father.