Russian Mi-28N from the Berkuty (Golden Eagles) helicopter display team fly in formation during the “Aviadarts” military aviation competition at the Dubrovichi range near Ryazan, Russia, August 2, 2015. The aircraft started dipping down due to back propeller failure and crashed, killing one of two pilots, according to a Reuters photographer and official representatives of the competition. The aviation contest is part of the International Army Games, which are held in Russia from the 1st till the 15th of August with participants from 17 countries, according to organizers. (Photo by Maxim Shemetov/Reuters)

A man wearing a traditional Russian costume holds a goose after a traditional goose fight during celebrations of Maslenitsa, also known as Pancake Week, which is a pagan holiday marking the end of winter, in Suzdal, Russia on February 29, 2020. (Photo by Maxim Shemetov/Reuters)

A man wearing a face mask walks past a picture of a Russian tank in central Moscow on June 18, 2020. Russia's President Putin on June 24 will preside over a massive military parade to mark Soviet victory in World War II, which was postponed due to the coronavirus pandemic. (Photo by Yuri Kadobnov/AFP Photo)

A local resident fills in documents near a mobile ballot box outside her house during a seven-day vote on constitutional reforms, in the village of Troitskoye in Moscow region, Russia on June 25, 2020. (Photo by Evgenia Novozhenina/Reuters)

A scene showing one of the first trench battles is prepared for the opening of the 3D Panorama exhibition “Memory talks. The road through war” in the former Sevcabel port in St. Petersburg, Russia, 16 September 2019. Various 3D dioramas – containing genuine wartime items such as aircraft, tanks and artillery in original size – allow visitors to walk through scenes from the beginning to the end of WWII without any museum barriers. The exhibition opens from 19 September 2019 to May 2020. (Photo by Anatoly Maltsev/EPA/EFE)

People walk on the street in Samara, Russia on July 18, 2017. (Photo by David Mdzinarishvili/Reuters)

Children fall as they slide down on a float along a chute to cross a pool of water and foam during the “Letniy Gornoluzhnik” (Summer mountain puddle rider) festival at the Bobroviy Log Fun Park near the Siberian city of Krasnoyarsk, Russia, August 23, 2015. The annual competition marks the end of the summer season at the Siberian ski, rest and entertainment resort. (Photo by Ilya Naymushin/Reuters)

Russian opposition leader, Alexei Navalny (C), reacts as the court delivers the verdict in his trial, in the city of Kirov, Russia, 18 July 2013. Alexei Navalny was sentenced to five years in jail for theft on Thursday, an unexpectedly tough punishment which supporters said proved President Vladimir Putin was a dictator ruling by repression. (Photo by Valentina Svistunova/EPA)