All flights into Donetsk international airport have been temporarily suspended after several dozen armed men seized control of the airport in the early hours of Monday morning, a news report said.
Armed representatives of the Donetsk People's Republic stormed the airport on Monday, demanding the withdrawal of Ukrainian troops stationed there, but no shots were fired, news outlet Ostov reported, citing the airport's press service.
The airport said in a statement published on its website that flights would be resumed at a later point, though no indication was given as to when this might be.
The airport seizure comes a day after Ukraine held its long-awaited presidential elections, in which chocolate magnate Petro Poroshenko claimed victory despite the official results having yet to be published.
Rebels in the eastern regions of Donetsk and Luhansk vowed beforehand not to acknowledge the outcome of Sunday's election, with the organizers of a referendum in Donetsk in May claiming 90 percent of voters had supported secession from Ukraine.