A Pakistani official says a serial killer may have been behind the rape and murder of young girl whose killing sparked deadly clashes between protesters and police.

Rana Sanaullah, the home minister for Punjab province, says 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.

Eight-year-old Zainab Ansari went missing last week while heading to a nearby home for religious 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.