Hundreds of students in Afghanistan rioted on Wednesday over reports that interrogators at America's Guantanamo Bay prison placed copies of the Koran on toilets.

A number of people were killed and many were injured after police opened fire to break up the demonstration in Jalalabad.

Protesters caused widespread damage to property in the eastern city.

Demonstrators also set fire to an effigy of US President George Bush, while the US authorities say they are investigating the allegations.

The city is now said to be calm, but many aid workers and non-essential UN staff are being withdrawn.