Iran ? The Iranian government stepped up its crackdown on supporters of presidential challenger Mir Hossein Mousavi on Sunday as violent protests continued for a second day over the disputed result of Friday’s presidential election.

There was no word on casualties or deaths, but gunfire could be heard in the evening from the vicinity of Vanak Square, where angry Mousavi supporters had clashed earlier with police, militia and Ahmadinejad supporters.

The government declared Saturday that President Mahmoud Ahmadinejad had been re-elected by a 2-to-1 margin — despite a record-breaking turnout many analysts had expected to favor Mousavi.

Mousavi hasn’t been seen in public since Friday, and his supporters said they worried he may be under some form of house arrest. Other reformist politicians were reported to have been rounded up.

Ahmadinejad, asked about Mousavi, did not explicitly guarantee his safety. “There is rule of law in this country, and all the people are equal before the law,” he said.