(CNN) U.S. military cargo planes gave 50 tons of ammunition to rebel groups overnight in northern Syria, using an air drop of 112 pallets as the first step in the Obama Administration's urgent effort to find new ways to support those groups.

Details of the air mission over Syria were confirmed by a U.S. official not authorized to speak publicly because the details have not yet been formally announced.

C-17s, accompanied by fighter escort aircraft, dropped small arms ammunition and other items like hand grenades in Hasakah province in northern Syria to a coalition of rebels groups vetted by the US, known as the Syrian Arab Coalition.

All pallets successfully were recovered by friendly forces, a U.S. official said.