Protests have been going on since the 12 June presidential election. Photo by EPA/BGNES
About 140 Iranians detained during protests against last month's disputed election result have been released from Evin prison, BBC reported, citing officials.
About 200 others, accused of more serious crimes, remain in the prison.
The release comes after Iran's supreme leader ordered the closure of another detention centre because it failed to "preserve the rights of detainees".
Officials also announced on Tuesday that 30 people were killed in clashes between opposition supporters and police - up from a previously stated figure of about 20.
No well-known political figure was among the people released on Tuesday, he said.