At least two people were killed and several others injured on Wednesday after riots erupted in a city in southeastern Pakistan following the rape and killing of a minor girl, officials and local media said.
Much of the anger was directed at Punjab Chief Minister Shehbaz Sharif and Punjab Inspector General of Police, who protesters claimed had failed to act on dozens of cases of children being raped and murdered in Kasur.
The police have yet to arrest the killers, though people protested after every incident. The two protesters were killed after police shot at an angry crowd attempting to storm a police headquarters in Kasur, about 20km south of Lahore.
Zainab's mother added: "I want justice".
My wife is even more aggrieved than I am over the heinous crime, Chief Justice Nisar remarked. "We are not here to hurt anyone". He is found as relative of the little princess Zainab.
According to reports by Pakistani TV channels, the girl was raped and then apparently strangled to death.
Zainab went for study to her tuition center but did not go back to her home.
Zainab, who lived in the city of Kasur in Punjab province, was kidnapped by a mysterious man on January 5 on her way to a tuition center, CCTV footage showed.
An eight-year-old girl was murdered after sexual assault in central Pakistan and her body was dumped in a trash bin, sparking a violent protest in the area and a nationwide outcry.
While speaking after the funeral prayer, Dr Tahir-ul-Qadri said that the brutal murder of a minor girl was an insult to humanity.
Ansari's case has attracted the attention of the country's civilian and military leadership, with Pakistan's chief justice calling for a police report within 24 hours, according to a Supreme Court statement.
"Arrest the culprit and start the investigation against them", he said.
Cops, however, have sought to reject the criticism.
The view got further strengthened when the investigators found close resemblance between the man in the CCTV footage of Zainab and the culprit's sketch in the police record.
Kasur district police officer Zulfiqar Ahmed defended the police response to Zainab's kidnapping. The city's streets were filled "stench of burning tyres", an Express Tribune report said.
Nobel Peace prize victor Malala Yousafzai, condemned the murder of Zainab, saying "such brutal incidents have to stop".
Former Pakistani cricketer Shahid Afridi was among those who commented on Twitter. What a shameful day for us, Zainab's killers must not only be hanged, they should be given such exemplary punishment that people should remember the lessson for ever.
The demonstrators have accused police of failing to act over the child murders.