New front opens in Syria as rebels say al Qaeda attack means war

BEIRUT (Reuters) - Syrian rebels said on Friday the assassination of one of their top commanders by al Qaeda-linked militants was tantamount to a declaration of war, opening a new front for the Western-backed fighters struggling against President Bashar al-Assad's forces.

Rivalries have been growing between the Free Syrian Army (FSA) and the Islamists, whose smaller but more effective forces control most of the rebel-held parts of northern Syria more than two years after pro-democracy protests became an uprising.