Ukrainian officials have suggested Russian links to the two attacks in February 2018. Ukraine's then-foreign minister, Pavlo Klimkin, said at the time that the attacks on the Hungarian center in Ukraine's western Transcarpathia region, where over 100,000 ethnic Hungarians reside, were attempts to destabilize the country.
An armed conflict in Ukraine's eastern industrial heartland flared up in April 2014, weeks after Russia annexed Ukraine's Crimean Peninsula. More than 14,000 people have been killed in fighting between Ukrainian forces and Russia-backed separatists.
The Hungarian center in the city of Uzhhorod was attacked with Molotov cocktails and partially destroyed by fire. The group's leader, Michal Prokopowicz, 29, was given a three-year prison term. Tomasz Szymkowiak, 23, was sentenced to two years in prison. Both had pleaded not guilty.
The third man, Adrian Marglewski, 26, cooperated with investigators and was given two years of supervised release and 40 hours of community service. Prokopowicz is a member of Poland's far-right, pro-Russia party, Zmiana. The two other men are members of a similarly radical group, Falanga.
The verdict announced Monday is subject to appeal.