MOSCOW (AFP) — Russia on Wednesday battled a major cross-border incursion from Ukraine for a second day, the most serious attack on Russian territory by Kyiv’s forces in months that prompted both countries to evacuate several thousand civilians.

A local state of emergency was introduced in Russia’s Kursk region on Wednesday evening, 36 hours after Ukrainian soldiers, tanks and armored vehicles stormed into the western border region.

Russia said it launched air and artillery firepower to repel the attack throughout Wednesday, after having rushed reinforcements to the region in a bid to halt Ukrainian advances.

After two days of fighting, the extent of the damage and the depth of the Ukrainian advance was unclear — though several reports from Ukrainian and Russian military bloggers suggested the fighters had gained several kilometers.

Some Russian military bloggers were reporting Ukrainian troops had reached the town of Sudzha, some eight kilometers from the border, and were shelling it constantly.

The small town of about 5,000 people is home to the Sudzha metering station, the last major transit point for Russian pipeline gas still heading to Europe via Ukraine.

President Vladimir Putin said Ukraine had indiscriminately attacked civilian buildings and ambulances while Russia’s top general vowed to crush the incursion.

“The Kyiv regime has undertaken another large-scale provocation,” Putin said in a televised meeting with government officials.

Kursk governor Alexei Smirnov introduced a state of emergency in the region on Wednesday evening, a move that gives authorities additional powers to bring the situation under control.

At least five civilians have been killed and 31 wounded — six of them children — since the incursion began, Russian health officials said Wednesday.

Witnesses interviewed on Russian television said they had fled border areas in cars under drone fire.

Senior Ukrainian officials have not commented directly on the attack.

The Chief of Russia’s General Staff, Valery Gerasimov, said up to 1,000 combatants from Ukraine had been involved in the offensive, and that Russian forces had stopped them penetrating deeper into the Kursk region.

“The operation will end with the enemy’s defeat and them being pushed back to the state border,” he told Putin in a televised meeting.