Isis attacks Syrian bases

Syria's President Bashar Assad. Photo / AP

Isis has used military equipment seized from Iraq in its biggest challenge yet to Assad regime forces.

Fighters from Islamic State have attacked two major military bases in the northeast of Syria and regime-held areas near Aleppo. They seized most of one base before coming under retaliatory aerial bombardment, holding regime officers and in at least one case decapitating him, according to pictures on social media.

The attacks mark a significant shift in the Syrian civil war. While the regime and Isis have fought in the past, both have until now preferred to focus their energies on the so-called "moderate rebels" comprising the Free Syrian Army and Islamist groups. The attacks suggest Isis has, for now, abandoned plans to move further into Iraq or attack Baghdad.