An 11-year-old Christian Pakistani girl said to suffer from a mental disorder could face the death penalty under the country's notorious blasphemy laws, after she was accused by her neighbours of deliberately burning sacred Islamic texts.

Rifta Masih was arrested on Thursday, after complaints against her prompted angry demonstrations, and Asif Ali Zardari, the president, has ordered the interior ministry to investigate the case.

As communal tensions continued to rise, around 900 Christians living on the outskirts of Islamabad have been ordered to leave a neighbourhood where they have lived for almost two decades.

On Sunday houses on the backstreets of Mehrabadi, an area 20 minutes drive from western embassies and government ministries, were locked with padlocks, their occupants having fled to already overcrowded Christian slums in and around the capital.

One of the senior members of the dominant Muslim community told the Christians to remove all their belongings from their houses by September 1. "I don't think anyone will dare go back after this," said one Christian, Arif Masih. "The area is not safe for us now."