The United Nations High Commissioner for Human Rights has expressed “grave concern” at the execution of a 20-year-old Iranian man for crimes he allegedly committed as a child.

Louise Arbour urged Iran to “respect its international legal obligations and the strong international consensus against the execution of minors.”

A crowd of 6,000 people are reported to have attended Makwan Mouloudzadeh’s funeral on Friday.

He was executed on Wednesday in a prison in the province of Kermanshah in western Iran.

Ms Arbour said that Iran is a signatory to international conventions banning the execution of people who were under the age of 18 years when they committed the crime they are charged with.

Iran leads the world in executing juvenile offenders, persons under 18 at the time of the crime, and is known to have already executed two juvenile offenders this year.

In May Branch Seven of the Penal Court of the city of Kermanshah sentenced Mouloudzadeh to death for raping three boys in 2000, even though all of his accusers had recanted their statements and he had repudiated his confession as being coerced by the police.

Mouloudzadeh was convicted as a juvenile offender.

During the trial, all of Mouloudzadeh’s accusers recanted their accusations against him and Mouloudzadeh himself testified that any confessions that he had made to the police about the alleged crimes were coerced and false.

The judge did not accept their testimonies and sentenced Mouloudzadeh to death.