A prominent opponent of Russia's annexation of Crimea has been given eight years in jail for stirring up protests.
Akhtem Chiygoz, deputy chairman of the Crimean Tatar parliament, the Mejlis, took part in a rally backing Ukraine's interim government in 2014. Clashes between rival protesters left two dead.
His lawyer said the sentence was unlawful and that he would seek his client's extradition to Ukraine.
Russia banned the Mejlis last year.
The Turkic-speaking Tatars make up 12% of Crimea's population and their 33-member parliament was legally recognised by Ukraine in 1999. But Russia said it was an extremist organisation.
When Ukraine President Viktor Yanukovych was ousted in 2014 after months of protests, Russian forces invaded the peninsula. Many Tatars fled, including the head of the community, Mustafa Dzhemilev, while there have been several reports of disappearances.
The EU and Amnesty International say the human rights of Crimean Tatars have since been violated. A group of four Tatars was this year convicted of being members of a banned Islamic group, Hizb ut-Tahrir.
Crimea's Supreme Court on Monday found Chiygoz, who was arrested in January 2015, guilty of organising mass riots in the city of Simferopol.
His jail sentence was immediately condemned by Ukraine's president, Petro Poroshenko, who wrote on Facebook: "You can illegally restrict freedom, but you can never break free will and truth! You can occupy another's land, but it will burn beneath your feet and seethe until it is liberated."