Kiev: Ukraine suspects the Russian military or its separatist rebel proxies were responsible for blowing up a warehouse storing tank ammunition at an eastern military base early on Thursday morning, Defence Minister Stepan Poltorak said.

Fire and explosions caused the detonation of ammunition in several sites at the base, possibly set off by a drone attack or a radio or timed device, Poltorak told a press conference.

Nobody was hurt but around 20,000 people have been evacuated from the surrounding area in the eastern Kharkiv region. Firefighters have struggled to douse the flames and explosions at the site continue, sending clouds of thick grey smoke into the sky.

"We have a 'friendly' country - the Russian Federation," Poltorak said. "I think that first of all it could be representatives who help the (separatist) groups that carry out combat missions," he said.