By Frances Harrison
BBC News, Tehran
All but three of the 33 Iranian women activists arrested earlier in the week in Tehran have been freed.
Seventy people were arrested at a demonstration last June
They have been warned not to take part in any protests to mark International Women's Day on Thursday.
The 33 were arrested on Sunday after demonstrating against sexual discrimination outside a courthouse.
They were showing solidarity with women on trial over an anti-discrimination protest in 2006. Humans rights advocates had condemned the arrests.
The New York-based organisation Human Rights Watch said they were part of increasing persecution and prosecution of activists in Iran who are calling for the repeal of laws that discriminate against women.
Two of the activists and their lawyer are still in jail but the rest of the women arrested on Sunday were freed in the middle of the night.
The families of two other activists were visited at night by the authorities and asked to sign pledges that the women would not demonstrate on International Women's Day.
One of those released from jail said she was too scared to join any protests now but the women's group still say they plan to gather in front of the parliament.
The decision to arrest so many prominent women in one go for peacefully holding up placards outside a court has won the Iranian government much negative publicity internationally.
Women activists say they have been subject to increasing intimidation since they launched a campaign to collect 1m signatures on a petition to change discriminatory laws like polygamy and child custody, which normally goes to the father in Iran.