Russia was forced to edit a social media statement claiming it had “defeated” Ukrainian forces staging a massive cross-border raid as fighting entered its third day.

On Tuesday morning, Ukrainian forces stormed across the border in an unprecedented thrust from the country’s regular army.

By Wednesday afternoon, they had captured the village of Sudzha, which is crucial for Moscow’s shipments of natural gas to Europe.

Moscow initially claimed a Ukrainian sabotage unit had “tried to gain a foothold directly on the territory adjacent to the state border”, but was beaten back by Russian forces, and after suffering “significant losses” retreated across the Ukrainian border.

However, it tweaked the post on the Telegram messaging app to remove any reference to any Ukrainian defeat.

It prompted criticism from war bloggers who accused the Russian defence ministry of delivering “overly optimistic assessments of the situation”.

“It is possible to make mistakes. You cannot lie,” the Two Majors Telegram channel wrote.

The Washington-based Institute for the Study of War said the edits were made to “likely avoid backlash from making demonstrably false claims about the scale and tactics of the ongoing Ukrainian penetration”.

By Wednesday night, Kyiv was said to have amassed more than 1,000 troops and had captured the village of Sudzha and nearby Malaya Loknya.

Ukrainian forces had created a salient some 10 miles deep and about six miles wide, according to Russian sources.

Vladimir Putin, the Russian president, took personal control over the situation during a meeting of government officials on Wednesday.

Russia’s defence ministry claimed Ukraine had lost “up to 400 servicemen and 32 armoured vehicles, including a tank” during the past 24 hours of fighting, in an update shared on the Telegram messaging app on Thursday.

Its statement added that Moscow’s ground and air forces were continuing to “suppress” Ukrainian troops crossing the border from Ukraine’s Sumy region.

However, Russian military bloggers painted a different picture, complaining that Kremlin forces had not been able to halt the cross-border raid.

Rybar, a Russian blogger with more than one million followers, wrote late on Wednesday: “It has not yet been possible to contain the enemy’s onslaught in the Kursk region.”

Videos emerged on social media purporting to show the capture of troops from Russia’s 225th assault brigade and fighters from the Chechen Akhmat special forces unit by Ukrainian forces.

There were also reports from several Russian militant bloggers that the Wagner Group were also being deployed to the Kursk region to help regular Russian forces halt the Ukrainian push.

The pro-war  Trinadtsatyy Telegram channel shared a video of what it claimed was Wagner fighters “returning to Russia”. The mercenaries have mostly been posted overseas since its former leader Yevgeny Prigozhin staged an ultimately failed coup last year.

Government or military officials in Kyiv have yet to officially comment on the incursion.

However, Mykhailo Podolyak, a presidential adviser, said Ukrainian operations in “Russian border regions” would improve Kyiv’s position in any future peace talks with Moscow.

“When you increase Russian losses... when you ramp up their war costs, such as destroyed military equipment, lost territory, lost people, will this affect how they perceive their war? Without a doubt,” he said.

The adviser also signalled that Ukraine had been given a tacit blessing by the US and Germany for the assault after armoured vehicles donated by the two nations appeared to have entered the battle.

“Our partners finally realise that everything connected to Ukraine’s military actions is our sovereign right and a step toward de-escalation and the final end of this war,” Mr Podolyak said.