Amnesty International has called on Iran to stop persecuting people who campaign for women's rights.
Iran's leaders say women are better off in Iran than anywhere
The human rights group says activists involved in a big campaign to improve women's rights have been targeted.
In a new report, Amnesty says women activists have suffered an "acute" backlash since the campaign was launched in August 2006.
Iran's President Mahmoud Ahmadinejad has insisted women in his country are treated better than anywhere else.
The so-called Campaign for Equality aims to collect a million signatures for a petition to push for an end to discrimination against women.
But Amnesty says those involved in it have suffered harassment, intimidation and imprisonment. Dozens of women have been arrested.
Among those persecuted, according to the group, are Ronak Safarzadeh, jailed without charge since October after her arrest at a meeting to collect signatures.
Delaram Ali, 23, was sentenced to nearly three years in prison and 10 lashes for participation in an illegal gathering, says the Amnesty report, though the punishment was suspended while her case is re-examined.
"Instead of intimidating and imprisoning women's rights campaigners, Iran should be unlocking the potential of its female population," said Amnesty's Tim Hancock.
A women's magazine was closed down earlier this year, accused by the authorities of endangering the spiritual, mental and intellectual health of its readers.
Amnesty says this is part of a wider crackdown on dissent in Iran, although it concedes that women have benefited in some way since the Islamic revolution of 1979.