Explosions were heard in and around Syria's Hama airport on Friday, Syrian state media said, without elaborating on the cause of the blasts, and a monitoring body said 11 pro-government troops were killed.
The Syrian Observatory for Human Rights, a Britain-based war monitor, said the series of explosions happened inside Hama's military airport and had been heard in Hama city.
Eleven people had died and dozens were missing from among Syrian government and allied forces.
"Five blasts at least were heard inside Hama military airport ... targeting ammunition and fuel depots," the Observatory added.
The war monitor said it wasn't clear whether the blasts had been caused by technical failure inside the depots or an attack. Thick plumes of smoke could be seen above the airport, it said.