Russian troops are preparing for a big attack in the Luhansk region of eastern Ukraine, officials warned on Monday night, urging a mass evacuation. 

“We see that equipment is coming from different directions, they are bringing manpower, they are bringing fuel,” the local governor Sergiy Gaida said in a video statement.

“We understand that they are preparing for a full-scale big breakthrough,” he added.

The White House said on Monday night that Russia was likely to “deploy tens of thousands of soldiers” in eastern regions with the next phase of war lasting “months or longer”. 

Gaiday urged residents to leave the region as soon as possible.

“Please don’t wait for your homes to be bombed,” he said in a separate video.

“Do not hesitate,” he added, specifying that 1,000 people had been evacuated on Monday.

A senior Pentagon official said Russia has removed about two-thirds of the troops it had around Kyiv – who were mostly sent back to Belarus with plans to redeploy elsewhere in Ukraine.

“The bombardments are becoming ever denser. Last night there was an attempt to break through at Rubizhne (near Lugansk). (But) our defenders repulsed and put several tanks out of action – there were dozens of (Russian soldiers’) corpses, Gaiday said.

“Yesterday, sadly, two volunteers were killed in a mine or mortar explosion,” he went on, adding “a church was bombed.”

The mayor of Borova, Oleksandr Tertyshnyy, whose town is midway between Luhansk and the main eastern city of Kharkiv, said local authorities “had to take a decision to evacuate the population… for citizens’ security. Those who can leave in their own vehicle are encouraged to do so,” he said on Facebook.