Pro-Russian insurgents commandeered six Ukrainian armoured vehicles and hoisted Russian flags over them, dampening the government’s hopes of re-establishing control over restive eastern Ukraine.

Ukraine has taken its first military action against a pro-Russian uprising in the east as government forces repelled about 30 gunmen at an airport, beginning what the president called an “anti-terrorist operation” to restore authority in the region.

Army troops have restored control over a small airport in eastern Ukraine that had been occupied by pro-Russian militiamen, the acting president said.

Pro-Russian insurgents dug in across eastern Ukraine, fortifying their positions around seized buildings and erecting fresh barricades even as Ukrainian tanks took up positions outside one eastern city now controlled by armed men.