ST. PETERSBURG, October 12 (RIA Novosti) - Scientists from Russia's central observatory near St. Petersburg have denied a prediction that a giant comet will collide with the Earth in late October, a spokesman for the Pulkovo Observatory said Thursday.

Some media reported earlier this month that Russian astronomer Nikolai Fedorovsky has predicted an October 28 collision of a huge comet with the Earth, which will allegedly unleash devastating tsunamis, earthquakes and avalanches.

Sergei Smirnov, an observatory spokesman said: "Our research does not support media reports that a comet will collide with the Earth in late October."

Smirnov said the astronomer Fedorovsky, who even failed to name the scientific institute he belongs to, is simply seeking publicity.

He said astronomers currently observe potentially dangerous celestial bodies using special search systems.

Smirnov said objects larger than 100 meters in diameter or more are considered dangerous. If one were to hit the Earth, it would cause a regional disaster comparable to the explosion of the Tunguska meteorite in Siberia in 1908.

Objects larger than one kilometer in diameter would cause a continental catastrophe, he added.

"A collision with an object larger than 10 kilometers in diameter would cause a global disaster," Smirnov said. "Such disasters occur once in dozens of millions of years, and are followed by serious climatic changes."

He said a large asteroid could approach the Earth in 2028, and said that if it then changes orbit, the possibility of a collision on its next rendezvous with the Earth in 2030 would increase.