Many residents in Donetsk fear they will be trapped on a battlefield between advancing Ukrainian troops and pro-Russian rebels who have vowed to make a stand.

Ukrainian forces have been pushing rebel units back towards their two main urban strongholds Donetsk and the smaller Luhansk.

Kyiv has encircled rebel positions in the two cities and are getting ready to move in on the two rebel strongholds.

This comes as the so-called prime minister of the self-proclaimed Donetsk People’s Republic, Alexandr Boroday, has resigned.

Boroday said: “As you may know I come from Moscow. I think that the Donetsk People’s Republic, Donbas, should be led by someone who is a real, blood and bones Donbas native.”

On Thursday, NATO’s secretary general called on Russia to pull back from the brink of war with its neighbour. He was visiting Kyiv in a show of support for Ukraine.

Political analyst Volodymyr Fesenko commented: “This visit came amid reports about the possibility of Russian invasion in Ukraine and the possibility of so-called “peacekeeping operation” in Donbas. Rasmussen’s visit is a clear political message – you should not do this”.

Meanwhile the acting chief international observer in Ukraine said that several groups of young men in military clothing had crossed back and forth between Russia and Ukraine.