KRAMATORSK, Ukraine (AP) — In the first Ukrainian military action against a pro-Russian uprising in the east, government forces repelled an attack Tuesday by about 30 gunmen at an airport, beginning what the president called an “anti-terrorist operation” to try to restore authority over the restive region.

The central government has so far been unable to rein in the insurgents, who it says are being stirred up by paid operatives from Russia and have seized numerous government facilities in at least nine eastern cities to press their demands for broader autonomy and closer ties with Russia. Complicating the political landscape, many local security forces have switched to their side.