He was detained at around 10:45 am (0715 GMT) after being stopped by three security personnel, two in uniform and one in plainclothes. One was carrying a walkie-talkie, the witnesses said.

Pouladi, who was riding pillion on a motorcycle when he was stopped, was in the process of making a telephone report to FRANCE 24 on rallies marking the anniversary of the November 4, 1979 storming of the US embassy in Tehran by Islamist students.

The rider of the motorcycle said the security force officials confiscated the reporter's mobile phone and then escorted him away.

Since then his whereabouts have been unknown.

AFP has been in touch with the Ministry of Culture and Islamic Guidance which coordinated foreign media coverage of the rally.

Officials there gave AFP assurances that they are tracking Pouladi's case.

Reporters without Borders estimate there are still around 30 journalists in detention in Iran, especially since the huge street protests that followed the disputed June elections that have prompted the current backlash against the foreign media.

Canadian-Iranian journailst Maziar Bahari was released on October 20 after 118 days' detention after making what Reporters without Borders said was a forced confession, in which he described all foreign journalists as spies.