Militant leaders from Islamic State (IS) and al Qaida have agreed on a plan to stop fighting each other and work together against their opponents, a high-level Syrian opposition official and a rebel commander have said.

A car bomb has exploded in eastern Syria near the border with Iraq, killing at least five people including a local rebel commander, activists say.

Fighters from an al Qaida-linked Syrian rebel group beheaded an allied commander whom they mistook for a pro-government fighter, activists say.

A team of reporters from Sky News Arabia has gone missing in the contested city of Aleppo in northern Syria.