"As a result of strikes carried out by the Russian armed forces, 74 Ukrainian military ground facilities were destroyed," said Igor Konashenkov, a defence ministry spokesman.

Destroyed facilities included 11 airfields, three command posts and 18 radar stations of the S-300 and Buk-M1 anti-aircraft missile systems, he said.

He added that a Ukrainian military helicopter and four drones had also been shot down.

Konashenkov said separatist forces continued an offensive backed by air support of the Russian armed forces.

Currently "armed groups of nationalists" are putting up resistance, he said, claiming that Ukrainian troops wanted to leave the area of hostilities.

He said that Defence Minister Sergei Shoigu had ordered Russian troops to "treat Ukrainian servicemen with respect".

Putin launched an offensive on Ukraine in the early hours of Thursday after a national address aired at around 5:40 am local time (0240 GMT).