Dutch Foreign Minister Maxime Verhagen has summoned an Iranian diplomat to protest against Tehran's bloody post-election crackdown and called for the immediate release of detainees.

"It cannot be that peaceful demonstrations are broken up violently," said a statement issued by Mr Verhagen's office after his meeting with Iranian chargé d'affaires Majid Ghahremani. "People in Iran must be able to protest peacefully and the Netherlands has asked that the arrested demonstrators be freed immediately."

Mr Verhagen asked Iran to probe complaints of election fraud as the Netherlands had "serious question marks" over the reliability of the results. "Minister Verhagen also protested against interference with foreign journalists and the arrest of a Dutch television crew," said the statement.

Listen: Minister Verhagen talks to RNW's John Tyler

The minister told NOS TV that the Iranian diplomat did not appear impressed by the Dutch complaint, but the message had certainly come across, Mr Verhagen added.

Violence erupted in Iran on Monday during massive rallies protesting against the re-election victory of hardline President Mahmoud Ahmadinejad. At least eight people were reported killed.

Independent Amsterdam-based Farsi station Radio Zamaneh reports that its sources in Iran are finding it increasingly difficult to feed the station's newsdesk with new information. "They're afraid and dare not mention their name. So they prefer a pseudonym when they're reporting what's going on in Iran, or they remain anonymous," a Zamaneh staff member told NOS TV. The station can be heard in Iran via satellite, on Hotbird 13 degrees east,  12476 MHz, Polarization horizontal, S/R 27500, or via the internet.

(afp, nos)