Russia’s defence ministry said on Wednesday that it had beaten back Ukraine’s forces with “air strikes, missile forces, artillery fire and active actions by units covering the state border”.

It also claimed Ukraine had lost “260 militants and 50 armoured vehicles, including seven tanks”.

The Telegraph could not independently verify these claims.

Fury over defence ministry’s failure

Following talks with his security chiefs, Putin appointed Denis Manturov, the Russian deputy prime minister, to oversee the response to the cross-border raid.

Despite the claims from Moscow that the situation was under control, Russian military bloggers issued a furious response at the defence ministry’s failure to secure Kursk.

Anastasia Kashevarova, a blogger with 250,000 subscribers, said: “We knew that the Ukrainian armed forces would go to Kursk Oblast. We knew that they were pulling forces together. We knew everything as usual, the guys from the fields reported it, but the higher-ups did nothing.”

Russian sources speculated that Ukraine was intent on advancing as far as the Kursk nuclear power plant, about 68 miles from the border, in revenge for the seizure of the Ukrainian plant in Zaporizhzhia.

Explosions were heard in Kurchatov, where the nuclear power station is located, local Telegram channels wrote, sharing what they claimed to be video footage taken by a resident.

Alexander Sladkov, a Russian war correspondent, wrote: “Why does the Ukrainian armed forces need the Kursk nuclear power plant? It will come in handy. There are many options.”

He added that Ukraine could demand that Russia leave the occupied plant in Zaporizhzhia in exchange for its forces leaving Kursk.

Western analysts said the Ukrainian operation was unlikely to achieve war-defining results or even drag significant resources away from Russia’s offensive in eastern Ukraine.

“A limited operation might be able to achieve limited goals, but a more ambitious operation carries greater risks. It is unlikely this operation will have a significant effect on the course of the war,” Rob Lee, a senior fellow at the Foreign Policy Research Institute, a US think tank, said.

Mick Ryan, a former Australian general, said: “One potential driver is political. The government of Ukraine wants to shift momentum and the strategic narrative, and have directed such an operation.

“Another potential driver is operational. That is, to draw away Russian forces from the Donbas to defend on the Kursk axis. However, given Russian advantages in manpower, Russia can probably cover both with limited impact on its operations in eastern Ukraine.”