MOSCOW, November 17. /TASS/. Russia’s Supreme Court declared on Monday Ukrainian National Assembly — Ukrainian People's Self-Defense (UNA-UNSO) and the Right Sector as extremist and banned their activity in the country.

Other Ukrainian organizations which have been added to the Russian blacklist include the Ukrainian Insurgent Army (UPA) and Stepan Bandera All-Ukrainian Organization 'Tryzub'.

The court announced the decision following a session, which had been held behind closed doors as some materials are classified. The court upheld an earlier claim filed by the Prosecutor General’s Office.

In March 2014, when UNA-UNSO became part of the Right Sector ultranationalist party, the Russian Investigative Committee launched criminal cases against some of its members, including Right Sector leader Dmytro Yarosh and MP Oleh Tyahnibok.

Russia’s investigators announced in early last month they have irrefutable evidence implicating members of the Right Sector nationalist group in mass killings of civilians in eastern Ukraine.