An “anti-terrorist” operation began in the eastern Donetsk region today and pro-Ukraine forces have now surrounded some of the separatists who captured government posts on the weekend.

Acting President Turchynov had given pro-Russian militias until Monday to disarm or face a “full-scale anti-terrorist operation” by Ukraine’s armed forces and at first didn’t follow through on the pledge. About 10 towns or cities had offices or headquarters seized and now the government has begun to react.

A report from Itar Tass News Serves says Ukraine forces have surrounded Slovyansk. A separate report from RT says the military has stormed an airfield in Eastern Ukraine and that men have been wounded.