It Was Just an Accident director Jafar Panahi reacts to screenwriter's arrest

One of the Oscar-nominated screenwriters of the Iranian drama It Was Just an Accident has been arrested in Tehran.

The detainment comes just weeks before the Academy Awards.

Representatives for the film shared the news that Mehdi Mahmoudian had been arrested on Saturday. No details on the charges against him were given.

Several days ago, Mahmoudian and 16 others signed a statement condemning Islamic Republic leader Ayatollah Ali Khamenei and the regime's violent crackdown on demonstrators.

Two other signatories were also arrested.

It Was Just an Accident director, Jafar Panahi, issued a statement on Sunday, decrying his co-writer's arrest.

"Mehdi Mahmoudian is not just a human-rights activist and a prisoner of conscience; he is a witness, a listener, and a rare moral presence - a presence whose absence is immediately felt, both inside prison walls and beyond them," Panahi wrote.

Panahi was also a signatory on the 28 January statement, which reads in part: "The mass and systematic killing of citizens who bravely took to the streets to bring an end to an illegitimate regime constitutes an organised state crime against humanity."

It Was Just an Accident, made covertly in Iran, was the Palme d'Or-winner at last year's Cannes Film Festival. It is nominated for Best Screenplay and Best International Film at the 15 March Oscars.