Iranian security forces rounded up at least seven prominent pro-reform activists, opposition leaders said Monday.
They government is stepping up a crackdown on the country's pro-reform movement, one day after eight people were killed in anti-government protests.
One of the dead is the nephew of the chief opposition leader. Reza Mousavi said Monday that the body of his brother, Ali Mousavi, was taken overnight from a Tehran hospital. He said that nobody had accepted "responsibility" for removing the corpse.
The opposition said President Mahmoud Ahmadinejad won the election in June through massive vote fraud and that presidential contender Mir Hossein Mousavi was the true winner.
The violence is some of the worst since disputed presidential election that sparked weeks of demonstrations. It erupted again over the weekend when security forces fired on stone-throwing protesters in the center of Tehran.