Russia declares ‘federal-level’ state of emergency in Kursk region after large-scale invasion from Ukraine and sent reinforcements, four days after hundreds of Ukrainian troops crossed the border, in the biggest offensive on Russian soil since the war began.

Russia’s defense ministry said reinforcements were heading to the Kursk region to counter the Ukrainian incursion. Russia sent Grad multiple launch missile systems, artillery and tanks, the RIA-Novosti news agency reported, citing the Defense Ministry.

Ukrainian troops have made rapid advances in recent days, reportedly penetrating up to 35 kilometers into Russian territory, according to the independent US-based Institute for the Study of War.

Rybar, a Russian military blog, reported that Ukrainian units were going from village to village and setting up ambushes against Russian reinforcements.

In fact, Kiev launched a massive attack with drones, hitting an air base and destroying ammunition depots in the city of Lipetsk, which is located deeper in Russian territory.

“The operational situation in the Kursk region remains difficult,” Kursk Governor Alexei Smirnov told Telegram.

Two days after the chief of the military staff Valery Gerasimov reported to President Vladimir Putin that the advance had stopped, the Russian Defense Ministry said its forces “continue to repel an attempted incursion by the Armed Forces of Ukraine into the territory of the Russian Federation.”

More than a thousand soldiers along with around thirty tanks and armored vehicles from Ukraine’s Sumy region north of Kharkiv are believed to have crossed the border into Russia’s Kursk region on Tuesday.

While Kiev has not officially claimed responsibility for the attack, President Volodymyr Zelensky said on Thursday that Russia must “feel” the consequences of the ongoing war in Ukraine. Zelensky, in fact, praised his army for its ability to “surprise” and succeed, without, however, explicitly referring to Kursk.

While pro-Ukraine militias made up of Russian nationals opposed to Putin, such as Russia’s Freedom Legion, have carried out several cross-border raids in the past, this is the first attack involving Ukrainian troops.

Russia’s sluggish response

Moscow has come under fire for its slow response to the Ukrainian attack – mainly because Russian forces were thought to have strengthened their defense lines in the wake of previous incursions into the Belgorod region last year.

A military blogger linked to the Kremlin claimed that Russian forces repeatedly warned their military command about Ukrainian forces massing along the border with the Kursk region, but failed to prepare for a possible invasion, he told the Institute for the Study of War .

Communication problems within the Russian military may be to blame for the lackluster response, Grant said, adding: “Nobody wants to tell the boss bad news, so they lie, and eventually when the truth comes out, it’s already too late. Putin doesn’t really know what’s going on.”

Why Ukraine invaded Russia

As analysts explain, Ukraine may be seeking to remove Russian forces from the frontline of the battle in eastern Ukraine or to capture and hold Russian territory to use as a bargaining chip.

At the same time, Kiev may also seek to lure Russian warplanes to Kursk, where they may be vulnerable to its ground-based air defense missiles and prevent them from conducting operations against Ukraine’s recently acquired F-16 fighter jets from the West.

The surprise ground attack on Russian soil is partly, they say, about “bringing the war inside Russia and undermining Putin and the credibility of the military.”