Rubizhne

Ukrainian forces prepared on June 24 to retreat from the strategic city of Severodonetsk after weeks of fierce fighting, a setback that could pave the way for Russia to seize a larger swath of eastern Ukraine.

Ukrainian forces are facing "massive" and relentless artillery attacks in a battleground eastern city, Kiev warned, as Russian troops gained ground throughout the Donbas region.

Moscow's troops have been pummelling eastern Ukraine for weeks and are slowly advancing, despite fierce resistance from the outgunned Ukrainian military.