Pro-Russian rebels in the eastern Ukrainian city of Donetsk say they are not giving in despite being one of the last remaining separatist strongholds.

They claim 1,200 new Russian trained recruits are on their way and that a new counter offensive is being planned.

Ukraine’s President Petro Poroshenko told his security council he blames the rebels and their foreign supporters for the continuing violence.

“Since mercenaries and terrorists are temporary people in Luhansk and Donetsk, they have nothing that may connect them to these cities. So the worse the situation is the better it is for them. I am fully convinced that the blame for the destruction lies solely on rebels and their foreign sponsors,” he said.

There has been more heavy fighting near Monday’s attack on a convoy carrying refugees fleeing the violence.

Government troops trying to seal off supply routes into Luhansk have accused rebels of launching rockets at the buses causing the deaths of dozens of civilians.