Inam Ghani, the additional inspector general of the Punjab police, said that Kasur is a peculiar case “because there have been serial pedophile murders.”

In January 2018, Zainab Amin, 7, was raped and killed in Kasur. Her body was found in a trash site. Before her, 12 other child rape cases had been reported within roughly a mile radius. In 2015, a gang of men was arrested after reports emerged that they had sexually abused at least 200 children in a rural area of the district. The men made videos of the abuse to either sell underground or use to extort money from victims’ families.

Zainab’s murder had also incited days of angry riots in Kasur, and the government and leading political parties, including Mr. Khan’s Pakistan Tehreek-e-Insaf party, vowed never to let such attacks occur again. After 12 days, the police arrested a 24-year-old neighbor named Imran Ali. An antiterrorism court sentenced him to death in February 2018. He was hanged later that year.

It was widely expected that the case of Zainab, which had become a symbol of child sexual abuse, would result in broad police overhauls and awareness of such crimes.

But more than a year later, there is no letup in reports of child abuse in this district and in the country.

“There is no child protection policy in Punjab,” said Sarah Ahmad, chairwoman of the government-run Punjab Child Protection and Welfare Bureau, adding that there was a need for tougher legislation against child abuse.