LONDON: The UN Human Rights Office said it is alarmed at reports that Iranian authorities are refusing to release the bodies of dead protesters to their families.

The rising number of deaths during the ongoing anti-regime protests in Iran, in the face of an intensifying crackdown by security forces, underscores the critical situation in the country, spokesman Jeremy Laurence said.

He expressed concern about the reports that the bodies of protesters were being held hostage by security forces unless the families agree to remain silent about the death of their loved ones or go along with false narratives about the cause.

Relatives who visited morgues to retrieve the remains of a loved one reportedly have been pressured into supporting state media accounts suggesting the deceased was a bystander or member of a militia who was killed by rioters, sources told the BBC.

Last week, officials took the body of 14-year-old Sepehr Maghsoudi from a morgue hours after he was shot dead during a protest in the southwestern city of Izeh, a source close to the family told BBC Persian. Security officers told relatives they would not release the body because they were grieving and “people may do something,” the source said.

Many families have publicly accused security forces of killing their relatives during the protests, only to later change their stories and agree with official accounts of the causes of death. This has prompted speculation on social media and elsewhere that statements were being coerced.

The mother of nine-year-old Kian Pirfalak, who was shot dead last Wednesday in Izeh, was heard at his funeral saying he was killed by security forces. Officials insisted he died in a “terrorist” attack. Later that same day, his mother appeared on state television to retract her comments and warn that they should not be “misused.”

Footage from the northwestern city of Javanrud on Monday reportedly showed the body of a protester being transported in a pickup truck, the BBC reported. His family was said to have refused to allow the body to be taken to a mortuary where it could be stolen by officials.

More than 300 people have been killed during the protests over the past nine weeks, including more than 40 children, according to the UN Human Rights Office. In addition, at least six people connected with the protests have reportedly been sentenced to death on charges of “waging war against God” or “corruption on earth.”

“We urge the authorities to address people’s demands for equality, dignity and rights — instead of using unnecessary or disproportionate force to suppress the protests,” said, Laurence the UN human rights spokesman.

“The lack of accountability for gross human rights violations in Iran remains persistent and is contributing to the growing grievances.”

The office has called on Iranian authorities to release all those detained simply for exercising their right to protest and drop all charges against them.