Russian investigators believe that the February 6 explosion in the Moscow metro, and another one in a suburban train in Yessentuki (southern Russia) in late 2003 "are links of the same terrorist chain." "The techniques used are identical: in both cases, the terrorists used powerful bombs they planted in train cars," a source close to the investigation team told RIA Novosti.
The source also confirmed that the attackers used bulk explosive, which the suicide bomber carried on him/her or in a bag. The weight of the explosive was preliminarily estimated at 5 kilos.
The Moscow blast killed 39 people; the Yessentuki attack, 47.
Twenty years later, the cause of death of 118 Kursk submariners remains a mystery. the Russian navy was unable to save the dying men.