Twenty people including, eight Basij members, have been killed during the post-election unrest in Tehran, Iranian officials say, reported Press TV.
All the Basij members were killed by gunfire, indicating that there were gunmen fomenting unrest among protesters, the officials said.
The volunteer Basij forces were among the main targets of the rioters during the recent protests in Tehran.
Iranian police have arrested a rioter who attacked an unarmed Basiji member during the post-election protests in Tehran.
The rioter says he attacked the man because he had been provoked by bad news on the death of a student called Mohsen Imani.
Some reports had said five students, including Imani, were killed when police and Basiji forces stormed Tehran University's dormitories last Sunday.
Mohsen Imani, however, is alive and says he was not in the dormitory at the time.