Iran has arrested several opposition figures, a day after at least eight people died during the most violent protests for months.
Those detained include some of opposition leader Mir Hossein Mousavi's closest aides, a former foreign minister and former President Mohammad Khatami, the BBC reports.
Mr Mousavi's nephew was among those killed during Sunday's confrontation in Teheran. Seyed Ali Mousavi's family said he had been shot in the back.
Opposition sources have accused government agents of taking his body in order to prevent his funeral becoming a rallying point.
State media says the authorities are conducting forensic tests on his and four other bodies.
Iran's Supreme National Security Council and state media said eight people were killed across Iran during Sunday's demonstrations, while earlier, Persian TV reported 15 had died.
The official death toll is the highest since June, the BBC reports.
The opposition says thousands of demonstrators took in the anti-government protests, though the numbers cannot be independently verified because media restrictions.
The fatalities are the first in street protests since the demonstrations immediately after President Mahmoud Ahmadinejad's controversial re-election in June.