A criminal investigation into extremist activity against Russia has been launched against members of the Ukrainian organization Right Sector, which is outlawed in Russia, the press service of the Russian Investigative Committee has said.

The Right Sector has more than 5,000 members, it said.

"Over the period from no later than 2014 and until today, the leaders and activists of the Right Sector organization have been regularly and systematically plotting and committing crimes directed against the Russian Federation, its citizens and its diplomatic missions in the territory of Ukraine, as well as against the Russian-speaking civilian population," the committee's press service said in a report, seen by Interfax on Friday.

It has already been established that the organization includes more than 5,000 combatants, among them citizens of Ukraine, Russia and other countries, and the organization has its structural divisions - the headquarters coordinating its activists at the local level - in each of Ukraine's regions, the press service said.

The information available to investigators also indicates that the Right Sector's leaders have set up the organization's units in countries of Europe and North America.

"The agency reports that a criminal case has been opened against Right Sector leaders Dmytro Yarosh, Andriy Tarasenko, as well as this organization's senior members Andriy Stempitsky, Valeriy Voronov, Artyom Skoropadsky and other persons based on the collected evidence under Part 1 of Article 282.2 of the Penal Code of the Russian Federation [an extremist organization's activity]," the press service said.

Russian citizen Artyom Skoropadsky, who is Right Sector's spokesman, is an active member of this organization and "systematically appears in the media and on the Internet, as well as attending various large-scale public events in order to promote the criminal ideology of the Right Sector organization and call on like-minded people to join it and participate in committing extremism-related crimes," the Russian Investigative Committee said.

"It has been established that the Right Sector, which was founded by Dmytro Yarosh in 2013, adopted the views of radical Ukrainian nationalism, expressed Russophobia and fascism. And the organization's goal became 'resisting Moscow aggression by military methods,' which is in fact a justification for the use of violence along political, racial, ethnic and religious lines," it said.

The Right Sector includes the leaders and activists of a number of Ukrainian far-right organizations and movements such as the Stepan Bandera Tryzub, the Ukrainian National Assembly-Ukrainian People's Self-Defense (UNA-UNSO), Brotherhood, the Social-National Assembly, White Hammer, Group S15, the Carpathian Sich, the Ukrainian Insurgent Army and the Ultras association of football fans, the committee said.

"Staying in the territory of Ukraine, Yarosh, Tarasenko, Stempitsky, Voronov, Skoropadsky and other heads of the Right Sector organization's structural divisions still continue their criminal actions with the Ukrainian leadership's mute approval and encouragement," it said.

It was reported that Russia accused Yarosh of public calls for terrorist and extremist activity. He was arrested in absentia and was declared internationally wanted.