The UN condemned Iran for the execution on Thursday of a man who was convicted of murder when he was a teenager, as the country closes out 2020 with a blitz of executions. UN spokesperson Ravina Shamdasani said Mohammad Hassan Rezaiee was executed for a fatal stabbing allegedly committed when he was 16. Executions of child offenders are “prohibited under international law”, she said. “There are deeply troubling allegations that forced confessions extracted through torture were used in the conviction of Mr Rezaiee, and there are numerous other serious concerns about violations of his fair trial rights,” Ms Shamdasani said. Rezaiee was the fourth confirmed execution of a child offender this year, she said. The spokesperson for the UN human rights office urged “Iranian authorities to halt all executions of child offenders and immediately review their cases”. "The UN has repeatedly urged Iran to cease the appalling practice of executing child offenders, but we understand that at least 80 child offenders remain on death row," Ms Shamdasani said. Eight inmates from various Iranian prisons were executed between December 19 and 26, Ms Shamdasani said. At least eight other death row detainees are at risk of "imminent execution", she said. Iran’s mission to the UN in New York did not immediately answer a request for comment. According to the pressure group Amnesty International, Mr Rezaiee was being held at Lakan Prison in Rasht after being convicted in a grossly unfair 2008 trial for the fatal stabbing of a man in a group fight the previous year. Before the execution early on Thursday, Amnesty used Twitter to urge Iran’s supreme leader Ayatollah Ali Khamenei and others to “halt his execution now and ensure a fair retrial in accordance with the rules of juvenile justice”. According to Amnesty, Iran executed more than 250 detainees in 2019. China, Iran, Saudi Arabia, Iraq, Egypt, the US and Pakistan were the most prolific users of capital publishment.