A Russian court Thursday sentenced a student in the far eastern city of Birobidzhan 6,000 kilometres (3,700 miles) from Ukraine to five years in prison for passing troop locations to Kyiv.

The unnamed man collected information "using the internet" on "Russian troops and locations of military units in the zone of the special military operation" in Ukraine in return for payment from Kyiv's SBU security service, Russia's FSB security service told the RIA Novosti news agency.

The court found the man guilty of treason but reduced his sentence to 5 years in a strict-regime penal colony plus one year of community sentence because he pleaded guilty and cooperated with the investigation, the FSB said.

Treason is punishable by up to life in prison.

Since the start of its military offensive in Ukraine in 2022, Russia has cracked down on all Kremlin critics and opponents of the military action.

It has also issued lengthy sentences on charges of collaboration or espionage for Kyiv.

Birobidzhan is the main city of Russia's Jewish Autonomous Region, which was created in the early Soviet era as a Jewish homeland but now has only a very small Jewish population.