But with Monday's twin blasts which the authorities have blamed on two female suicide bombers with links to the Northern Caucasus, they appear to have returned to spread fear in Moscow for months to come.
It was women laden with explosives who killed a total of 185 people in targeted bombings on a Russian special forces barracks in 2002, and a Moscow rock concert in 2003 and who struck in a double suicide attack on aircraft in 2004.
They were also involved in the 2002 three-day siege of the sold-out Moscow Dubrovka theater, where bereaved mothers and widows strapped with explosives made up 19 of the hostage-takers.
"We know very little about the lives of these women before the terror attack: what pushes them to do it," said Alexander Cherkasov, an analyst for the North Caucasus region for rights group Memorial.
"My impression is that more often than not, vengeance is what pushes them to die -- vengeance for their loved ones, for themselves."
Investigators said they found suspected body fragments from female suicide bombers at the sites of Monday's twin blasts.
One of the bombers appeared to be a young women between 18 and 20 years of age with brown eyes and swarthy complexion, a law-enforcement source was quoted by the Interfax news agency as saying.
Their twin bombs, packed with metal shrapnel, exploded with a force of up to three kilogrammes of TNT equivalent, according to officials.
Grigory Shvedov, the chief editor of the web site www.caucasianknot.info, said the bombers appeared linked to an Islamist martyr brigade known as Riyad as-Salikhin (Garden of the Righteous), which became known in 2002 after storming the Dubrovka theater and taking some 850 people hostage.
Women numbered 19 of the 41 hostage-takers in that group -- allegedly founded by Chechen rebel warlord Shamil Basayev -- dotting the red theatre seats, wearing black and bundled in deadly explosives.
The hostages' ordeal was ended after three days in an assault by police using debilitating gas, leaving 130 people dead.
"Women with relatives among the terrorists are behind most suicide attacks. They are more emotional: once they make a decision nothing can stop them," said Vladimir Vasiliev, head of the Russian parliament's security committee.
But Shevdov said suicide bombers had become more fundamentalist and no longer recruited exclusively among women suffering the loss of loved ones.
"It is no longer directly connected with personal loss, with the involvement of relatives. The separatist war has transformed into a religious one," he said.
Most of the insight into the women was obtained in 2003 when Zarema Muzhikhoyeva became the first would-be suicide bomber to be captured alive.
Her husband and father killed in clashes with Russia federal troops, the Chechen woman, then 22, told of being approached by a middle-age woman, drugged and kept in a safe house for a week before being sent to blow herself up at a McDonald's in central Moscow.
However, the TNT in her bag failed to detonate.
Authorities are now searching for two women accomplices to Monday's attacks -- shown on video surveillance footage escorting the female suicide bombers to the metro where they went alone to carry out the bombings.