(Reuters) – The leader of Russia’s Chechnya region, Ramzan Kadyrov, said on Sunday that Russian forces, led by a Chechen-based special forces unit, have seized control of a Ukrainian border village.

Kadyrov, who has led his South Caucasus region as a Kremlin loyalist since 2007, said the Akhmat-Chechnya unit led Russian troops in taking control of Ukraine’s Ryzhivka, in Sumy region, opposite the southern Russia region of Kursk.

Writing on the Telegram messaging app, Kadyrov said the “large-scale planned advance” inflicted “significant losses on the Ukrainian side, which was forced to retreat”.

Russia’s Defence Ministry issued no statement on the action and there was no comment from Ukrainian military authorities.

Reuters could not independently confirm the report.

The commander of the Akhmat unit was quoted by Russia’s TASS state news agency this month as saying his forces had been deployed in Russia’s border Belgorod border region – to the east of where Sunday’s capture was said to have occurred.

In May, Kadyrov said during a meeting with Russia’s President Vladimir Putin that tens of thousands of his soldiers were prepared to fight for Russia in Ukraine and that a total of 43,500 troops already have served in Moscow’s war against its smaller neighbour.

Ukraine’s military has warned in recent weeks of a buildup of Russian forces around Sumy region in preparation for military action.

(Reporting Bogdan Kochubey, Ron Popeski and Lidia Kelly; Writing by Ron Popeski; Editing by Will Dunham)