Said Buryatsky, a notorious gang leader in Russia's North Caucasus, killed in a special operation on Tuesday, was involved in the derailment of a Moscow-St. Petersburg train in November 2009, the head of the Federal Security Service said on Saturday.

Alexander Tikhomirov also known as Said Buryatsky and five other militants were killed during a special operation in the southern Russian republic of Ingushetia on March 2.

"DNA tests of the militants have been carried out to establish their involvement in the derailment of the Nevsky Express in November 2009. These materials allow us to consider them guilty of this crime," Alexander Bortnikov told Russian President Dmitry Medvedev.

The Nevsky Express high-speed train partially derailed on November 27, 2009 after a bomb equivalent to 7 kg (15 lbs) of TNT detonated on the track. The attack took the lives of 28 people and left over 90 injured.

Bortnikov said that police found a laboratory for making explosive devices and seized more than 1,000 kg of explosives, many small arms and ammunition at the site of the special operation in Ingushetia's Nazran district.

A police source told RIA Novosti that the gang was planning another major terrorist attack in the North Caucasus.

"Buryatsky himself was training suicide bombers," the source said.

According to investigators, Said Buryatsky was also the organizer of other large-scale terrorist attacks, including the assassination attempt on Ingush President Yunus-Bek Yevkurov in June 2009 and the suicide bombing in Nazran in August that left more than 20 policemen killed.

The FSB also reported that an Ingush treasury official was the financier of Said Buryatsky's gang.

SOCHI/MOSCOW, March 6 (RIA Novosti)