Police on Sunday claimed to have achieved a "breakthrough" in the rape and murder case of a 10-year-old girl who was found dead on Friday night in Karachi's Bin Qasim area.

The girl, a resident of Marshal Yard Railway Colony in Bin Qasim, had gone missing at around 6pm on Friday. Police claim that the family did not report her disappearance. The relatives themselves started a search and found her body — with her hands and legs tied — inside the water tank on the third floor of the building where no one was living.

The body was shifted to the Jinnah Postgraduate Medical Centre (JPMC) where doctors confirmed that she was raped and strangulated to death.

“The case has almost been cracked,” revealed DIG East Amir Farooqi.

He said the suspect, aged around 21, is a neighbour of the deceased child from the same apartment building. During an initial probe into the case, he "confessed" to raping and killing the girl.

The senior officer added that they were waiting for the DNA test's findings on samples taken from the held suspect to formally arraign him in the case.

The suspect told the investigators that he murdered the girl out of fear of being identified.

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Bin Qasim SHO Arif Razzak told Dawn that it was a purely residential colony for railway employees where outsiders could not roam easily. The fact that the girl’s body was found from the same building led them to believe that the neighbours may have been involved in her gruesome murder.

The officer revealed that police have detained at least 15 people from the building for questioning and their DNA samples were taken by doctors at the JPMC and sent to a laboratory for testing.

“An investigation has been launched and we are waiting for laboratory reports to establish the identity of the possible suspects,” he added.

The victim, a fourth-grade student, was the daughter of a UDC (upper division clerk) of the railways. The parents took her body for burial to their native town of Qambar-Shahdadkot.

Police have registered a case against unknown suspects on a complaint of the girl’s father.

DIG Farooqi told Dawn that police have added terror charges in the rape and murder case by invoking Section 7 of the Anti-Terrorism Act (ATA), 1997 which pertains to punishment for acts of terrorism.

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All 15 suspects are in police custody on a two-day remand sought from the concerned court. They will be produced before the court on Monday for further remand.

The senior officer said that the DNA reports of the held suspects were expected within the next three to four days.

“We will release all of them except three brothers of the same family when the DNA reports are received,” said DIG Farooqi.

He revealed that the primary suspect used to work at a coal unloading project as a supervisor at Port Qasim.

"There was no work for the last two weeks. He was waiting for a ship to come and was about to resume his job in a day or two," he said.

The minor girl's killing had angered area residents who while carrying her coffin staged a sit-in on main National Highway, demanding justice and immediate arrest of the killers.

Provincial Deputy Speaker Shehla Raza and lawmaker Mohammed Sajid Jokhio have given assurances to the family that the killers will be brought to justice.