The alleged kidnapping and murder of a seven-year-old boy in Mardan sparked protests on Sunday, with residents demanding the speedy arrest of the assailant.

District Police Officer Mian Saeed Ahmed said the boy was last seen playing in front of his house in the Tambulk area on Saturday before he went missing. A missing persons complaint was subsequently lodged with the police.

Early on Sunday morning, an unidentified suspect dumped a gunny sack holding the child's body in the fields behind the family's home and fled, the DPO said.

The boy was the son of a labourer who earns daily wages by loading and unloading vehicles at a nearby vegetable market, police said.

Police investigators cordoned off the crime scene and began collecting evidence.

The body was sent to Mardan Medical Complex for a post-mortem examination, hospital sources said, adding that DNA samples were collected from the body and sent to the Bacha Khan Medical College forensic laboratory for testing.

When the child's body was returned to his family, residents of the area blocked the Mardan-Nowshera Road with the body in protest, demanding the suspect's arrest.

The incident has caused a wave of fear, anger and grief to spread through locals. At least two similar cases have been reported in Mardan this year, in which minors who went missing and were recovered dead were believed to have been subjected to sexual assault.

As many as 17,862 cases of sexual assault against children have been reported throughout the country in the last five years, according to data presented to lawmakers in the National Assembly.