Syrian extremist group joins al-Qaida affiliate

An extremist group embroiled in infighting with one of the largest Syrian rebel groups has pledged allegiance to al-Qaida-linked militants, a move that threatens to deepen divisions in the already-disparate insurgency.

The extremist group Jund al-Aqsa has been battling the powerful Ahrar al-Sham group in northern Syria for days, after the latter accused it of ambushing its leaders.