KHARTOUM (AFP) - An AFP correspondent was released early on Wednesday after being taken away by Sudanese security agents at the University of Khartoum and held for more than 12 hours without charge.

Simon Martelli, a British national, was detained at around midday (0900 GMT) on Tuesday while talking to students and taking pictures at the university, in the city centre, where riot police have violently dispersed a string of protests in recent days.

The correspondent was taken to an office of the National Intelligence and Security Service (NISS) where he was interrogated and denied contact with the outside world.

Riot police had fired tear gas to disperse a demonstration outside Sudan's oldest university on Monday, where students were chanting anti-regime slogans and denouncing a sharp rise in food prices, according to eyewitnesses.