A former Ukrainian soldier who sent the location of sensitive military targets to Russia has been sentenced to five years in jail, Ukrainian prosecutors said Thursday.

Ukraine has arrested thousands of people on suspicion of collaborating with Russian troops since the war began in February 2022, many in the east and south of the country.

The man, whom prosecutors did not name, allegedly contacted a "representative of the Russian Federal Security Service (FSB)" using the Signal messaging app, prosecutors in the northeast Kharkiv region said.

He then sent the FSB the positions of soldiers and military equipment in the Kharkiv region and southern Mykolaiv region, they added.

"The enemy needed this information to conduct targeted air strikes on Ukrainian defenders," the prosecutors said.

The man was detained near the frontline town of Kupiansk and "fully admitted his guilt", they added.

Russia launched a fresh ground assault into the Kharkiv region last month, capturing pockets of territory across the border.

The United Nations said last year that Ukraine had opened more than 6,600 criminal cases "against individuals for collaboration and other conflict-related crimes" since the war began.

In May, Ukrainian security services detained six people accused of helping Russia strike an apartment building in the eastern Donetsk region, killing nine people.

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