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 comet, though some regard it as an explosion of a UFO.
• The Petrozavodsk phenomenon on September 20, 1977.
• The Height 611 UFO incident on January 29, 1986, was a supposed UFO crash which happened in Dalnegorsk, Primorsky Krai.
• The Voronezh UFO incident of 1989.
• The Sassowo explosions were two mysterious explosions which occurred on April 12, 1990, and July 8, 1992, equivalent to 25 tons TNT.[1]
• 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.[2]