UN rights chief 'horrified' by violent crackdown on Iran protesters

The United Nations rights chief said Tuesday he was "horrified" by the mounting violence directed at protesters across Iran, amid reports that hundreds have been killed.

Successive nights of mass protests nationwide since Thursday have posed one of the biggest challenges to the clerical leadership since the 1979 Islamic revolution ousted the shah.

UN High Commissioner for Human Rights Volker Turk urged Tehran to halt all forms of violence and repression against peaceful protesters, and to restore full access to the internet and phone services.

"The killing of peaceful demonstrators must stop, and the labelling of protesters as 'terrorists' to justify violence against them is unacceptable," Turk said in a statement.

While broad sections of Iranian society have taken to the streets demanding fundamental changes in how the country is run, "the authorities' reaction is to inflict brutal force", he said.

"This cycle of horrific violence cannot continue. The Iranian people and their demands for fairness, equality and justice must be heard," the UN rights chief said.

Turk said all killings, violence against protesters and other rights violations must be investigated in line with international human rights norms and standards -- and those responsible held to account.

He warned that several hospitals were reportedly overwhelmed by the number of casualties, including children.

"It also extremely worrying to see public statements by some judicial officials indicating the possibility of the death penalty being used against protesters through expedited judicial proceedings," he added.

Some reports indicated that members of the security forces have also been killed, he said.

Iranian authorities insisted they have regained control, but rights groups accuse the government of using live fire against protesters and masking the scale of the crackdown with an internet blackout.

The Norway-based NGO Iran Human Rights (IHR) said it had confirmed 648 people killed during the protests, including nine minors, and thousands more injuries, but warned the death toll was likely much higher -- "according to some estimates more than 6,000"

Turk's office does not have a presence in Iran but said it was receiving reliable information from sources on the ground. Its information so far points to hundreds killed, but it is unable to give a precise, verified figure.

US President Donald Trump, who has repeatedly threatened Iran with military intervention, announced Monday a 25-percent tariff on any country doing business with Iran.

"Iranians have the right to demonstrate peacefully. Their grievances need to be heard and addressed, and not instrumentalised by anyone," Turk added.