'This is big!' Ukraine's troops 'miles deep into Russia' after huge attack

Ukrainian forces are now "miles deep into Russia" after their successful attack on the Kursk region.

Russia has declared a "federal-level" emergency after the incursion and President Vladimir Putin denounced it as a “large-scale provocation."

Meanwhile, Ukrainian President Volodymyr Zelensky said Thursday that Russia needed to "feel" the consequences of the 2022 invasion.

Speaking to Sky News, military expert Professor Michael Clarke explained the significance of the incursion.

He said: "It began at dawn on Tuesday, and it looked like one of these freedom for Russia legion (an anti-Kremlin group) attacks.

"It looked like one of those attacks - a sort of pinprick attack - to embarrass the Russians and cause a bit of a problem.

"It looks as if the Ukrainians obviously decided to back this up... and within about 48 hours they were backing it up with apparently some quite big units."

He continued: "They (Ukraine) look as if they've taken over at least a dozen settlements.

"They've pushed in towards Sudzha, which is a logistical hub, and they've been fanning out, northeast and southeast from there.

"They're miles deep into Russia... and that's big - that's not just a raid.

"The Russians thought they could deal with it with a few of their reserve battalions...that's not happening".

Putin has sent reinforcements to the region in a bid to drive the Ukrainians back out of the territory.

Russia's military has said it is "continuing to repel" the attack, but the BBC reports that a 15-vehicle Russian convoy was damaged, burned, and abandoned during the fighting.

Meanwhile, Kursk acting governor Alexei Smirnov said on Telegram: “The operational situation in the Kursk region remains difficult."

Top adviser to Zelensky, Myhailo Podolyak, said Russia will now “start to realize that the war is slowly creeping inside of Russian territory."