Amnesty International said Friday, Iran is intentionally using lethal force to crack down on protests that erupted after the death of Mahsa Amini, adding that without international action more people risk being detained or killed.

Its warning came as another rights group said 83 people had been killed in two weeks of protests that started over Amini’s death following her arrest by morality police, as Iran pressed ahead with more detentions of prominent figures.

“The Iranian authorities have mobilized their well-honed machinery of repression to ruthlessly crack down on nationwide protests in an attempt to thwart any challenge to their power,” Amnesty said.

“Without concerted collective action by the international community that goes beyond statements of condemnation, countless more people risk being killed, maimed, tortured, sexually assaulted and thrown behind bars.”

It said its review of photos and videos showed “most victims were killed by security forces firing live ammunition.”

The NGO said it had obtained a leaked official document issued to the commanders of armed forces in all provinces on September 21 instructing them to “severely confront” protesters.

Another leaked document showed that on September 23, the commander of the armed forces in Mazandaran province, where some of the deadliest clashes have taken place, ordered security forces to “confront mercilessly, going as far as causing deaths, any unrest by rioters and anti-revolutionaries”.

Amnesty said it had confirmed 52 deaths in the protests but the toll was likely higher. Another rights group, Oslo-based Iran Human Rights, said that 83 people are now confirmed to have been killed.

Its warning comes as Iran presses ahead with an intensifying crackdown that has seen the arrest of many journalists, activists and other prominent figures.

Former Iranian international football player Hossein Manahi was arrested Friday after supporting the protests on his social media accounts, the state run IRNA news agency said.

Security forces also arrested singer Shervin Hajipour, whose song “Baraye” (“For”) made up of tweets about the protests went viral on Instagram, the rights group Article 19 and Persian-language media based outside Iran said.

His song, which racked up millions of views on Instagram and prompted many to comment that it moved them to tears, has now been removed from his account.

The Washington-based Committee to Protect Journalists says at least 29 journalists have been arrested in the crackdown.

These include two female reporters, Nilufar Hamedi and Elahe Mohammadi, who helped expose the case of Amini to the world by reporting respectively from her hospital and her funeral.