Human Rights Watch has condemned the hangings in Egypt of three young "political detainees" convicted of murdering the son of a judge, charging they had been tortured to confess.
The three men were executed in the northern city of Alexandria on Thursday, a security source told AFP, following a trial in which they stood accused of the 2014 murder and of having formed a "terrorist group".
The confessions of university students Ahmed Maher Hindawi and Almotaz Ghanem, and Abdel Hamid Metwalli, a computer shop owner, all members of the outlawed Muslim Brotherhood, were "extracted under torture, one of the defendants alleged in a leaked letter" to human rights lawyers and activists, HRW said.
"The letter indicates that the men were tortured by electric shock and beatings in detention," it added.
HRW's deputy Middle East and North Africa director, Michael Page, accused Egypt's authorities of having committed "a glaring injustice by executing three men who apparently gave 'confessions' extracted through electric shock and other torture".
He urged the government in Cairo to "immediately impose a moratorium on executions, which magnify the cruelty of unfair trials".
Human rights groups have repeatedly criticised President Abdel Fattah al-Sisi's government for cracking down on secular and left-wing activists, as well as Islamists close to the Muslim Brotherhood.
The crackdown was launched in 2013 after Sisi, then army chief, overthrew Egypt's first freely elected president, Mohamed Morsi, following street protests against the Islamist's turbulent one-year rule.