An Ukrainian military official said that Russia is preparing for the next stage of its offensive in Ukraine, after Moscow stated that its forces will intensify their military operations in “all operational areas”.

Russian missiles and shells rained down on a number of cities in strikes that Kyiv says have killed dozens in recent days.

Vadim Skibitsky, spokesperson for Ukrainian military intelligence, said yesterday, Saturday: ''It's not just missile strikes from the air and sea.. we can see shelling along the entire contact line, along the entire frontline. There is active use of tactical aviation and attack helicopters''.

He continued: ''There is already certain enemy activity along the entire frontline... It is clear that preparations are now underway for the next stage of the offensive”.

The Ukrainian army said that Russia is apparently regrouping its units to launch an attack on the symbolically significant city of Sloviansk, which is controlled by Ukraine in the eastern Donetsk region.

Ukraine says that at least 40 people have been killed in Russian shelling of urban areas in the past three days, as the war launched by Russian President Vladimir Putin on February 24 intensifies.