ALEPPO (Syria) • Syrians expressed horror and outrage yesterday at the brutal beheading of a child by a rebel group in Aleppo city, describing it as a "heinous act".

The horrific murder, captured in footage circulated on social media on Tuesday, was carried out by Islamist rebels who accused the boy of fighting alongside government forces.

"How could they slaughter a child like this?" said 25-year-old Bassel Zein, a barber in the opposition-held Al-Kalasseh neighbourhood of Aleppo. "He should have been tried in a fair way and maybe swopped with the regime for rebel detainees instead of this heinous act," he said.

The killing was condemned by the opposition Syrian National Coalition, which expressed "shock at the horrific scenes".

The boy was decapitated by members of the Nureddin al-Zenki rebel group on the back of a pick-up on a public road in Aleppo's opposition-controlled Al-Mashhad neighbourhood.

In the grisly footage, rebels accused the boy of fighting with a pro-regime Palestinian faction known as the Al-Quds Brigade and said he was captured during fighting north of Aleppo city. "This is a prisoner from the Quds Brigade. They don't have men any more, so they've sent us children today," one of the men said.

But the Al-Quds Brigade issued a statement denying the boy was a member, and describing him as a 12-year-old Palestinian refugee.

The Nureddin al-Zenki group officially condemned the act as a "violation" in a statement on Tuesday, describing it as an "individual mistake that does not represent the general policy of the group".

It said it had detained those involved in the murder and established a judicial committee to investigate the incident and issue a verdict "as soon as possible".

AGENCE FRANCE-PRESSE, REUTERS