Earlier pro-Russian rebels claimed to have seized the international airport in the city of Luhansa – as Ukrainian troops were reported to have withdrawn from the area.
It comes as Russian and Ukrainian officials meet with rebel leaders in Minsk for talks.
Ahead of the meeting the Russian Foreign Minister Sergei Lavrov urged all sides to make an “immediate ceasefire” their priority.
At least 2,600 people have been killed in eastern Ukraine since April.
Despite, Moscow's calls for a ceasefire, the fighting has intensified since Russia annexed Crimea in March this year.
