(CNN) -- Influencing events in Syria just got a lot harder for the Obama administration and its allies. Despite receiving months of training, diplomatic support and aid from the West, the Free Syrian Army's command has lost control of its headquarters and supply depots in northern Syria to the recently formed Islamic Front -- another sign that the balance among rebel forces is tipping toward militant groups away from more secular brigades.

The warehouses -- belonging to the FSA's Supreme Military Command (SMC) -- are at Bab al Hawa, a border crossing into Turkey. There are conflicting reports about just how they were taken over and what they held. The head of the SMC, Gen. Salim Idris, told CNN that only food and other humanitarian supplies were taken; other FSA officials say guns and two tons of ammunition were removed.