KYIV, Aug 6 - Russia said on Tuesday that Ukraine had launched an armored assault into Russia's southern Kursk region, but Moscow's forces had responded and the region's governor described the situation on the border as "controllable,” Reuters reported.

Ukrainian officials have not issued any comments on the raid, but Russian military bloggers, citing photo evidence and other sources, claimed that Ukrainian forced had advanced at least 7 kilometers into the Kurk region.

Kursk's acting governor Alexei Smirnov said five people were killed including two members of an ambulance crew, and at least 20 were wounded in the fighting. A senior human rights official said six children were among the injured.

Moscow's defense ministry said it had sent reserves to help repel hundreds of Ukrainian fighters backed by tanks, in what would be one of the largest ground incursions into Russian territory of the more than two-year-old war.

"The enemy today launched another attempt to break into the territory of Russia's Kursk region," the latest ministry statement said. "Artillery fire, army aviation strikes and drone strikes are being inflicted on the enemy."

Ukraine regularly fires artillery and missiles into Russian territory, and has hit targets deep inside Russia with long-range attack drones, but infantry raids are rare.

Forces describing themselves as voluntary paramilitaries fighting on Ukraine's side staged a major incursion into parts of Belgorod and Kursk region earlier this year. The purpose of those raids, which inflicted minimal damage, remains unclear.

Ukraine's general staff on Tuesday reported Russian strikes on border villages but made no mention of any Ukrainian offensive operation inside Russia.

Reuters was unable to verify battlefield accounts from either side.

Russia's defense ministry appeared to have deleted an earlier account of the attack in which it said a "Ukrainian sabotage group" had suffered heavy losses and retreated into Ukraine.

Official Russian social media accounts said that up to 300 Ukrainian fighters, backed by tanks, had attacked border units in two localities in Kursk - Nikolayevo-Daryino and Oleshnya.

Acting governor Smirnov said three Russian civilians had been killed initially, one by shelling and two by drones.

Writing on the Telegram messaging app late in the evening, Smirnov also said Ukrainian forces had shelled a border area, injuring two children. (rt/ez)