Iran's authorities have arrested more than 32 women activists protesting outside a courthouse in Tehran.
Seventy people were arrested at last June's demonstration
The protesters were showing solidarity with five women on trial for organising a protest last June against laws they say discriminate against women.
The five have been charged with endangering national security, propaganda against the state and taking part in an illegal gathering.
US pressure group, Human Rights Watch, has urged an end to the prosecution.
It said the women had been exercising their right to freedom of peaceful assembly.
The five are organisers of a demonstration last June which was violently broken up by the police and led to the arrest of 70 people, many of them innocent bystanders.
The BBC's Frances Harrison, reporting from the demonstration, says almost all the leaders of Iran's women's movement were arrested.
The women held up banners outside the revolutionary court, saying: "We have the right to hold peaceful protests".
The aim of the women is to draw attention to discriminatory Islamic laws on polygamy and child custody that often cause great suffering to women, our correspondent says.
When the five women on trial left the court building they were arrested again, along with their lawyer.
Parveen Adalan, one of those on trial, said her lawyer had not yet seen any of the evidence against her, although she has been questioned five times by the intelligence agencies.
"They didn't give them our documents to read, so we don't know what's happening," she told the BBC.
One of the women demonstrators, Nahid Mirhaj, accused the police of trying to intimidate them.
She said the police chief was "using obscene words and describing us as 'misfits'".
Our correspondent says police and plain-clothes security men chased away journalists and onlookers and then loaded the women onto a curtained minibus and drove them away.
The women believe the authorities are trying to intimidate them to prevent any kind of protest during International Women's Day on 8 March.