Russia has invaded Ukraine again, Lord Cameron warned, as troops crossed over the border to open a new front near the second city of Kharkiv.

Russia’s defence ministry said its troops had taken five border villages in the region, in what is believed to be the first time its forces had launched a cross-border attack since the initial invasion in 2022.

Ukrainian officials insisted that fighting was ongoing in those villages and Russia’s forces were being “contained” there.

Foreign Secretary Lord Cameron told Sky News: “It’s extremely dangerous. It only underlines that this a unjustified, illegal invasion by Putin into an independent sovereign country and he has now, as it were, invaded it again from the north of Kharkiv.”

The local governor of the border region under attack on Sunday morning said that more than 4,000 people have fled over the weekend.

Ukrainian officials had warned for weeks that Moscow might try to attack its northeastern border regions, pressing its advantage as Ukraine struggles with delays in Western aid and manpower shortages.

Follow the latest updates below and join the conversation in the comments section