New Delhi, Feb 20 (IANS): Russian armoured tanks painted with a letter 'Z' and huge convoys are moving towards the Ukraine border - as the eastern region is rocked by shelling, Daily Mail reported.

It is suspected the markings have been allocated for specific roles amid rising tensions over an imminent invasion, with footage showing the letters sprayed on tanks, self-propelled guns, fuel trucks and supply vehicles.

Independent Russian Telegram channel Hunter's Notes, which closely monitors military movements, said 'all equipment [marked with "Z"] was seen near Kursk and in the Shebekino region of Belgorod' on the border with Ukraine, the report said.

Around 200 military vehicles were spotted in the area, as 'Z' markings were 'applied hastily', with the channel suggesting 'we are dealing with a certain group of troops that has its own tasks and plans for the near future'.

It comes as explosions shook eastern Ukraine late on Saturday, after the NATO chief warned the signals coming out of Russia suggest that Moscow is readying for a 'full-fledged attack'.

Hundreds of artillery shells have exploded along the contact line between Ukrainian soldiers and Russia-backed separatists, further increasing fears that the volatile region could see a Russian invasion, Daily Mail reported.

Thousands of civilians have been evacuated from increasingly barraged front line regions, where Kyiv said two of its soldiers had died in an attack yesterday - the first fatalities in the conflict for more than a month.