A group of Syrian Sunni Muslim rebels linked to al-Qaeda have beheaded one of their own wounded fighters after mistaking him for a foreign Shi’ite fighting for President Bashar al-Assad, a monitoring group said yesterday.

A video posted by the Syrian Observatory for Human Rights shows two members of the Islamic State of Iraq and the Levant (ISIL) brandishing a severed head before a crowd in Aleppo and saying he was an Iraqi Shi’ite fighting for Assad.

Observatory head Rami Abdelrahman said that the man was later identified by the Ahrar al-Sham group, which fights alongside ISIL, as Mohammed Marroush, one of its fighters.

“(ISIL) admitted that they killed the rebel, and arrested a Tunisian man for cutting his head off,” Abdelrahman said, adding that the Tunisian had been referred to an Islamic rebel court in Aleppo.

Marroush had been wounded in fighting around Aleppo and taken to a hospital for treatment, where ISIL fighters said they had heard him repeat the name of two venerated Shi’ite imams, Ali and Hussein, Abdelrahman said.

Activists in Aleppo said that Marroush, who was anaesthetised, might have thought he had been captured by pro-Assad militiamen and so pretended to be a Shi’ite.

Many Shi’ites have come to Syria from Iraq or Lebanon to help Assad, whose ruling establishment are mostly members of a sect linked to Shi’ite Islam, fight a majority Sunni revolt.