Russia's Federal Security Service says the explosion that killed 40 people earlier this month on the Moscow metro was the work of a terrorist.
Russian news agencies quote the security service press office as saying that based on the type of explosives used, investigators have concluded the blast that ripped through a Moscow underground train on February 6 was definitely the work of a terrorist.
According to a summary report, investigators say the bomb was identical to one used to blow up a commuter train in the southern Russian city of Yessentuki in December. Forty-two people died in that attack and more than 200 were injured.
Russian authorities say they suspect Chechen separatist rebels were behind both incidents - a charge the separatists deny.
The Russian news reports say the bomb was carried by a suicide bomber, but offer no proof of the claim. Immediately after the attack, officials said a security video showed a suspicious-looking person who might have boarded the ill-fated train, and some survivors also referred to such a person.