Police Friday won permission to hold a young Christian girl accused of blasphemy in custody for a further 14 days while her case is investigated, officials said.

Rimsha was arrested in a poor suburb of Islamabad on August 16 after a neighbour accused her of burning papers containing verses from the Quran, in breach of Pakistan's strict blasphemy laws.

She arrived at court for the unannounced remand hearing in an armoured police van amid tight security, guarded by heavily-armed commandos and covered with a white sheet to conceal her face.

"She was produced in the court of a magistrate where we requested an extension of 14 days in her judicial remand," Munir Jafri, a police officer investigating Rimsha's case, told AFP.

"We wanted more time for further investigation and the court accepted our request."

Another hearing is scheduled for Saturday to decide on a bail application and whether to accept a medical report that said Rimsha is 14 years old, which would mean her case would be treated under juvenile law, and has a mental age below her actual age.

Some reports have said she has Down's Syndrome.

Tahir Naveed Chaudhry, one of Rimsha's lawyers confirmed to AFP that Rimsha was produced on Friday and remanded for a further 14 days, while Shamaun Alfred Gill, a spokesman for All Pakistan Minorities Alliance (APMA) said Friday's hearing was a "routine procedure".