Russia imposed a sweeping security regime in three border regions on Saturday as Moscow scrambled forces to counter Ukraine's biggest attack on Russian sovereign territory since the start of the war in 2022.
Ukrainian forces rammed through the Russian border early on Tuesday and swept across some Western parts of Russia's Kursk region, a surprise attack that may be aimed at gaining leverage in possible ceasefire talks after the US election.
President Vladimir Putin cast it as a major provocation and though Russia's top general, Valery Gerasimov, said on Wednesday that Ukraine's incursion had been halted, Russia has thus far failed to push the Ukrainian forces back over the border.
"The enemy has been halted so far - but that does not mean that it is all quiet there: there is serious fighting going on there," said Andrei Gurulyov, a lieutenant general who served in Soviet and Russian forces and is now a lawmaker for the ruling party.
Russian military bloggers said the situation had stabilized after Russia rushed in forces to halt the surprise Ukrainian advance, though they said Ukraine was swiftly building up forces and that there were intense battles underway.
The Ukrainian attack on Russia has prompted some in Moscow to question why Ukraine was able to pierce the Kursk region so easily after more than two years of the most intense land war in Europe since World War Two.
Ukraine has not commented directly on the attack, but video posted on Ukrainian media purported to show Ukrainian soldiers in control of a gas measuring facility in the border town of Sudzha, where Russian natural gas flows into Ukraine for transit to Europe.
Reuters could not verify the video. Reports from Russian sources said Ukraine was in control of some areas of Sudzha.
NUCLEAR PLANT
Alexander Bortnikov, the director of the Federal Security Service (FSB), ordered an anti-terrorist regime be imposed on Kursk, Bryansk and Belgorod regions - which have a combined area of nearly 92,000 square km.
"The Kyiv regime has made an unprecedented attempt to destabilize the situation in a number of regions of our country," the National Anti-Terrorism Committee said, adding that there had been civilian casualties.
The measures essentially give the security services sweeping powers to lock down an area, including controls on communications and limits on a host of usual freedoms. Thousands of civilians have been evacuated from Kursk region.
Some reports said Ukrainian forces were pushing towards the Kursk nuclear power station, which supplies a major chunk of southern Russia's electricity. It has a total six reactors, two shutdown, two under construction and two operational.
The acting governor of Kursk region, Alexei Smirnov, said drone debris had fallen on a power substation near Kurchatov, the town which serves the Kursk nuclear station.
The head of the UN's International Atomic Energy Agency noted the "significant military activity" in the area and called for restraint.
Russian diplomats in Vienna told the IAEA that fragments, possibly from downed missiles, had been found, though there was no evidence of an attack on the station.
