Saying that Allah would forgive the man who mistakenly killed a fellow believer, the al Qaeda-linked Islamic State of Iraq apologized for the beheading of one of their allies, Mohammed Fares, a member of the rebel group Ahrar al-Sham on Friday.

“We call on God to accept Mohammed Fares into his Kingdom and to forgive his brothers that sought to rid us of the enemies of God and our enemies,” said Omar Al-Qahatani in a statement put out by the al Qaeda-affiliated Islamic State of Iraq and the Levant.

The mistake wasn’t found out until a video was posted online on Wednesday showing members of the Islamic State of Iraq holding the head of what they thought was a supporter of Syria’s Bashar Assad in Aleppo up in the air while one brandished a knife. One of the two men announced, “He is an Iraqi Shiite volunteer fighter in Bashar al-Assad’s army,” he said in Arabic. Other fighters recognized their fellow combatant and the mistake was revealed.

The mistake was made when Fares was taken to a makeshift hospital after being wounded in a clash outside of rebel-held Aleppo, and while there shouted what were thought to be the names of two Shitte associated figures. It was then that Sunni fighters assumed he was a government fighter and beheaded him.

Human rights groups condemned what they called barbaric actions by the group.