A senior rebel commander linked to al-Qaeda has been killed in a suicide attack in the Syrian city of Aleppo. Abu Khaled al-Suri was among several people who died in the attack on a compound of his militant group, Ahrar al-Sham, activists say.
Another militant group, the Islamic State of Iraq and the Levant, known as ISIS, is believed to be responsible. ISIS is engaged in a bloody power struggle with rival factions in the Syrian rebellion.
It has been engaged in violent clashes with other rebel groups since early January in which hundreds of fighters have been killed on both sides.
Ahrar al-Sham is a prominent, hard-line rebel group, part of a powerful alliance of seven groups known as the Islamic Front.
According to rebel and activist sources, the attack was carried out by one suicide bomber (or possibly two) who penetrated its headquarters in Aleppo.