An Iranian director arrested last summer – weeks before his latest film was released to widespread acclaim – has gone on hunger strike to protest his continued detention amid more than four months of anti-government protests.

Jafar Panahi, whose films have thrilled critics and won numerous international prizes, issued a statement saying he will refuse food and medicine “in protest against the extralegal and inhumane behaviour of the judicial and security apparatus”.

He is among a number of Iranian artists, sports figures and other celebrities detained after speaking out against Iran’s theocracy.

Such arrests have become increasingly frequent since nationwide protests broke out in September over the death of a young woman in police custody.

Panahi, 62, was sentenced to six years in prison in 2011 on charges of producing anti-government propaganda, though the sentence was never carried out.

Banned from both travel and filmmaking, he continued to make underground films which were released abroad to great acclaim.

He was arrested in July when he went to the Tehran prosecutor’s office to inquire about the arrests of two other Iranian filmmakers.

A judge later ruled he must serve the earlier sentence.

His latest film, No Bears, in which he plays a fictionalised version of himself while making a film along the Iran-Turkey border, premiered at the Venice Film Festival in September, a week before the protests began.

The New York Times and Associated Press named it one of the top 10 films of the year, while film critic Justin Chang of The Los Angeles Times called it 2022’s best movie.

The protests erupted after 22-year-old Mahsa Amini died while being held by Iran’s morality police for allegedly violating the country’s strict Islamic dress code.

The demonstrations rapidly escalated into calls for the overthrow of Iran’s ruling clerics, a major challenge to their four-decade rule.

On Wednesday, around 100 people took part in a protest in the western Iranian city of Abdanan, the semiofficial Tasnim news agency reported.

It said five “rioters” suffered minor injuries when security forces intervened and that 10 people were arrested.

Iran heavily restricts media access to demonstrations and periodically shuts down the internet, making it difficult to confirm specific incidents or gauge the scale of the ongoing demonstrations.

At least 527 protesters have been killed and more than 19,500 people detained since the demonstrations began, according to Human Rights Activists in Iran, a group which has closely monitored the unrest.

Iranian authorities have not released official figures on deaths or arrests.

Taraneh Alidoosti, the 38-year-old star of Asghar Farhadi’s Oscar-winning 2016 film The Salesman, was arrested in December after taking to social media to criticise the crackdown on protests.

She was released three weeks later on bail.