UFO sightings in Russia

The following are some alleged sightings of unidentified flying objects in Russia:
 * The Tunguska event of 1908, is considered to have been the explosion of a meteor, though some regard it as an explosion of a UFO.
 * The Petrozavodsk phenomenon on September 20, 1977.
 * In Usove in Soviet Ukraine, on October 4, 1982, a group of nuclear missiles became activated as a UFO hovered above the missile launch facility.
 * The Voronezh UFO incident of 1989.
 * The Sasovo explosions were two mysterious explosions which occurred on April 12, 1990, and July 8, 1992, equivalent to 25 tons TNT.
 * Early in 2012 a crashed titanium object, described as a "UFO fragment", was retrieved from a forest in the vicinity of Otradnenskoye, a rural locality in Novosibirsk Oblast, after strange sounds were heard there in December 2011. The smooth, silvery and U-shaped device, attached to a rounded section, and was not deemed to be related to space technology.