A Belgian couple have been kidnapped by bandits in southeast Iran who have demanded the release of their leader's brother in return for the hostages' freedom, Iranian FARS news agency reported on Monday.

Colonel Abbas Ebrahimi said the married couple had been kidnapped on Sunday by a bandit group led by Ismael Shahbakhsh in the area of Fahraj, a town that lies between the city of Bam and Iran's borders with Afghanistan and Pakistan.

"The kidnapper has given guarantees that in the case of the release of his brother from prison, he will release these two tourists," FARS quoted Ebrahimi as saying. The agency reported that the two Belgians had been taken to an undisclosed location.

The official Iranian news agency IRNA said the two Belgians went missing on a road between Bam, a historic city destroyed by an earthquake in 2003, and Zahedan near the border area.

The governor of Bam province, Majid Etemadi, said they were a married couple travelling by car.

An official at the Belgian embassy in Tehran said the mission was following up the reports but had no further information.

The southeast of Iran is notorious for clashes between the military and well-armed drugs smugglers. Parts of the region are dotted with trenches and machinegun posts.

Tourists visiting the area are advised not to travel at night. In the past, European and other tourists have been kidnapped there. Some were held by smugglers for weeks in a bid to secure the release of detained relatives.