Photo used for illustrative purpose.

Separately, it doubled a documentary maker's sentence for denouncing the Ukraine offensive.

Moscow has for more than two years led an unprecedented crackdown on dissent, comparable to Soviet levels of repression.

In the southern city of Rostov-on-Don, a court sentenced a 19-year-old to 12 years in prison for "treason," Russian state media reported.

The FSB security service said the teen had sent money to help Kyiv's army buy drones and food for troops, the RIA Novosti news agency reported. It said the defendant was arrested at an airport as he tried to leave Russia.

"The Rostov regional court found the man guilty and sentenced him to a punishment in the form of 12 years in a strict penal colony," RIA Novosti quoted the FSB as saying.

Russia regularly hands out long prison sentences to people it says are donating money to Ukrainian forces.

In Saint Petersburg, activist and documentary film-maker Vsevolod Korolev had his sentence more than doubled to seven years after both and he prosecutors appealed against his original jail term of three years for criticising the Ukraine offensive on social media.

Korolev has been in pre-trial detention since July 2022, accused of making "untrue" statements about massacres of civilians in Ukraine's Bucha. "Korolev believed his sentence to be illegal and unfounded," the press service of the court said, while prosecutors wanted his sentence to be raised to nine years.

"The appeal court changed the decision, increasing Korolev's punishment to seven years in prison." Before his arrest, Korolev made videos about people who had been jailed for speaking out against the Kremlin's offensive.

In Moscow, state media reported a man was detained for having a tattoo with a phrase making fun of the Russian army, coined in Ukraine at the start of the offensive. Russian police then published a confession video, in a practice that is still rare, in which he was made to publicly apologise.

Agence France-Presse