Iran has charged two prominent actresses for publishing pictures of themselves flouting the country's dress code for women, just weeks after announcing a crackdown on breaches, local media reported.

Police in Tehran have referred the case against Katayoun Riahi and Pantea Bahram to Iran's judiciary, accusing them of "the crime of removing the hijab in public and posting photos on the internet", the Tasnim news agency said late Monday.

If prosecuted, the pair could face fines or prison terms.

Earlier this month police said they would begin using "smart" technology in public places to crack down on women defying Iran's compulsory dress code.

Last week, photos of Bahram, 53, went viral after she posed without a headscarf at a film screening, while Riahi, 61, posted several photos taken in public places around Tehran in which she did not wear a headscarf.

The requirement for women to wear the headscarf in public was imposed shortly after the Islamic revolution of 1979.

The number of women in Iran defying the dress code has increased since a wave of protests following the September 16 death in custody of Kurdish-Iranian Mahsa Amini, 22, for allegedly breaching it.

On April 16, authorities said they had closed 150 commercial establishments whose employees were not complying with the dress code.

Ms Bahram and Ms Riahi have won several awards at Iran's leading cinema event, the Fajr International Film Festival.

In November, Ms Riahi was released on bail after more than a week's detention for posting photos to Instagram in solidarity with the Amini protests, showing herself without a headscarf.

She was the first Iranian actress to post such images on social media in support of the protest movement.