Iran has arrested ten more journalists in the past several days, opposition sources reported yesterday, in an apparent crackdown before expected protests this week.

At least 55 journalists are being held among the hundreds detained during the protests after President Ahmadinejad’s disputed re-election last year.

The arrests, along with the first executions of opposition supporters last week, come as security forces brace for more unrest on Thursday, the 31st anniversary of the Islamic Revolution. Thousands of opposition supporters are expected to clash with regime-sponsored marches across the country.

Eight demonstrators were killed in clashes with security forces during the last round of protests on the Shia festival of Ashura in December.

The protests began last June around the defeated presidential candidate, Mir Hossein Moussavi, over allegations of mass fraud in favour of Mr Ahmadinejad.

They quickly expanded into the “Green Movement”, posing the greatest internal threat yet to three decades of revolutionary rule. The regime has responded robustly, staging scores of show trials of opposition supporters accused of plotting with foreign enemies to bring down the regime.

Last week saw the first executions of opposition supporters alleged to have plotted the unrest with outside backing, sending a powerful warning to potential protesters this week.

Iran’s reformist leaders yesterday rejected the accusation of foreign backing and urged supporters to turn out for Thursday’s rallies.

“It has nothing to do with foreign powers,” Mr Moussavi said. “Iran’s Green movement is independent and will not in any way allow foreigners to interfere in its affairs.”