Russia has launched a major counter-offensive in an attempt to dislodge Ukrainian forces from its Kursk region.

Both Ukrainian and Russian sources said that Kyiv’s troops had started losing some of the ground they seized in the audacious incursion that began on Aug 6.

On Wednesday, Maj Gen Apti Alaudinov, who commands Chechen special forces fighting in Kursk, said Russian troops had gone on the offensive.

“The situation is good for us,” he said, according to Russian state news agency Tass.

“A total of about 10 settlements in the Kursk region have been liberated.”

Mash, a pro-Kremlin channel on the Telegram messaging app, reported that Moscow’s forces had advanced up to 150 square kilometres into the Ukrainian-held salient in a “local counter-offensive in the region”.

Other prominent Russian military bloggers said their country’s troops had seized control of Snagost, a village south of Korenevo on the Ukrainian left flank.

Battlefield footage shared on social media appeared to show at least eight armoured vehicles and tanks operated by Russia’s 51st Guards Airborne Regiment advancing on Snagost.

“It appears Russia was able to get the armoured force across the Seym River, despite Ukrainian strikes on the bridges,” Rob Lee, a senior fellow at the foreign policy research institute, a US think tank, said.

Kyiv had hoped by targeting bridges across the stretch of water it would hamper Russia’s ability to move troops and material to reinforce efforts to recapture lost territories across Kursk.

Moscow responded by building a series of temporary pontoon bridges across the water to replace the three main crossings.

Deep State, a popular Ukrainian war blog, also reported that Russians were able to launch the offensive after ferrying armoured vehicles across the river.

“The situation on the left flank of our group in Kursk worsened,” it wrote in a post late on Tuesday.

The blog, which has ties to the Ukrainian defence ministry, did not say whether Snagost had been lost in the fighting.

Prominent Russian military bloggers said Moscow’s forces were also advancing in the villages of Apanasovka and Byakhovo, south of the claimed capture of Snagost.

Russian sources also shared unverified clips of what they claimed to be the capture of Ukrainian prisoners of war caught in the advance.

Neither political or military officials in Ukraine made any public acknowledgement of the claimed Russian counter-offensive.

Russia’s defence ministry on Wednesday said Ukraine had sustained about 12,200 casualties in Kursk and lost nearly 100 tanks.

Meanwhile, Ukrainian forces continued to advance in other areas of Russia’s Kursk region, according to the US-based Institute for the Study of War.

The think-tank said geolocated footage had shown gains in eastern Komarovka, which lies south west of Korenevo.

Separate footage showed a Ukrainian advance south east of Vetreno, which is east of Korenevo.