The body of seven-year-old Zainab was found in a rubbish dump on Tuesday, several days after she went missing. She had been raped and strangled.
Angry demonstrators say the authorities are doing little to stem the spate of abductions, sexual assaults and killings.
Police in Kasur say there have been 12 similar murders in the past two years.
Eight-year-old Zainab had gone to her tuition centre but found murdered after rape. She is not the first one but Eimaan Fatima, Fouzia, Noor Fatima, Sanna, Asma & Laiba were kidnapped from Kasur in 2017, & their dead bodies were recovered from different parts of the city.Zainab's murder has sparked outrage across the rest of Pakistan. Well-known film and cricket stars demanded the killer be caught and the military offered support to the police.