DUBAI, June 15 (Reuters) - Saudi Arabia has executed a man for offences rights groups say he allegedly committed while under the age of 18, despite the kingdom"s insistence that it has abolished death sentences for many childhood crimes. Mustafa Hashem al-Darwish was arrested in May 2015 and charged with protest-related offences, many of which occurred when he was 17. He was executed on Tuesday in Dammam, a statement from the Ministry of Interior said. Saudi authorities said last year that they would stop sentencing to death people who committed crimes while minors, who would instead serve up to 10 years in juvenile detention, and would apply this retroactively. However, the March 2020 royal decree was never reported by state media nor published in the official gazette as would be normal practice. The state-backed Human Rights Commission told Reuters in February that the ban only applied to a lesser category of offence under Islamic law known as "ta"zeer." Darwish was convicted for "ta"zeer" offences. In his charge sheet, a copy of which was seen by Reuters, Darwish was accused of "participating in armed rebellion," "seeking to disturb security by rioting" and "sowing discord", among others. The evidence cited included a picture "offensive to the security forces", a signed confession and his participation in more than ten "riot" gatherings in 2011 and 2012. But the documents don"t specify the exact months of the alleged offences, and rights groups say Darwish was 17 at the time of his alleged participation in many of the protests. His case should have been reviewed under the reformed law, they say. Anti-death penalty charity Reprieve and Amnesty International said his confession was obtained under duress and that he recanted his confession, which he said was obtained through torture, in court. The Saudi Arabian government media office did not immediately reply to a request for comment. Reprieve said Darwish"s family received no advance notice and only found out he had been executed by reading the news online. "How can they execute a boy because of a photograph on his phone?," his family said in a statement. "Since his arrest, we have known nothing but pain. It is a living death for the whole family." Human rights groups and western lawmakers have repeatedly raised concerns about the implementation of the reforms. Earlier this month, a group of British MPs urged Foreign Secretary Dominic Raab to ask for a commutation of Darwish"s sentence on a visit to Riyadh, in a letter seen by Reuters. In a statement following Raab"s visit and meeting with Crown Prince Mohammed bin Salman, the UK foreign office said Raab had raised human rights concerns "notably around justice reform". read more