Al Qaeda fighters are massing at a Syrian town on the Turkish border in what appears to be an attempt to seize a vital crossing from rebels, activists said on Monday.

If the Nusra Front seizes the Bab al-Hawa crossing, they will control a key supply line to the Syrian rebels, dealing another blow to U.S. plans to build up a moderate rebel force capable of fighting both Islamic extremists and President Bashar Assad’s forces… […]