Suicide bombers struck two stations in Moscow's crowded Metro less than an hour apart Monday morning, killing at least 37 people and injuring 73, and bringing Russia's seething northern Caucasus directly to the Kremlin's doorstep.
The first bomb, equivalent to about four kilograms (8.8 pounds) of TNT, exploded at the height of morning rush hour and killed at least 25 people inside a train that had just pulled into the Lubyanka station, which is a two-minute walk from Red Square and located beside the headquarters of Russia's FSB security service, the former KGB. The second, smaller explosion, 45 minutes later on the same line, hit a train at Park Kultury, just across the street from a huge complex that houses the Kremlin news agency RIA-Novosti and the state-run English-language satellite network Russia Today.
An FSB spokesperson told journalists that "according to preliminary information, both blasts were carried out by female suicide bombers," who brought explosives onto crowded Metro carriages and set them off in what appears to have been a carefully planned and coordinated series of attacks.
Medvedev: what we have done before is not enough
President Dmitri Medvedev pledged to step up security in the Russian capital and to expand the security crackdown in the turbulent north Caucasus, which is the almost certain source of the threat.
"We will continue the operation against terrorists without hesitation and to the end," Mr. Medvedev said in televised remarks after the tragedy. "It is difficult to prevent such terrorist attacks and to provide security on transport," such as Moscow's sprawling and overcrowded Metro system, he said.
"It is necessary to tighten what we do, to look at the problem on a national scale, not only relating to a certain populated area but on a national scale. Obviously, what we have done before is not enough," he added.
Russian response quick, competent
Security experts offer cautious praise for Russian authorities who appear to have avoided mass panic with a quick and competent response that contrasts sharply with clumsy reactions to previous terrorist strikes in downtown Moscow early in the past decade. The areas were quickly cordoned off by police and thousands of shaken and frightened survivors evacuated from the stations – which are among the deepest in the city – in an orderly fashion, and helicopters were brought into the paralyzed city center to extricate the wounded.
"There is no mistaking the symbolism of the targets; first the security services and then the main center of state journalism," says Alexei Mukhin, director of the independent Center for Political Information in Moscow, whose own office is at Park Kultury. "The people who ordered these attacks were acting on a carefully thought-out plan."
Viktor Ilyukhin, deputy chair of the State Duma security committee, says the attacks are almost certainly the result of deteriorating security conditions in the northern Caucasus, Russia's mainly-Muslim southern flank where a growing extremist insurgency has been spreading, largely below the world's radar screen, for the past couple of years.
"The terrorists are aiming at destabilization, their goal is the frighten the population," says Mr. Ilyukhin. "They also want to take revenge for the actions of the security forces against them, for the arrests and liquidations of their leaders," in the north Caucasus region, which includes the turbulent republics of Dagestan, Chechnya and Ingushetia, he says.
Violence in north Caucasus a decade-long threat
Violence in the north Caucasus has been spiking in recent weeks, including half a dozen bombings in Dagestan this month alone and two attacks by Ingush insurgents against local officials, most of which is scarcely reported even in the Russian media.
Some experts suggest the Moscow attacks might have been revenge for the tough security crackdown by Russian forces in the north Caucasus, which officials say have resulted in the killing of at least 35 leaders of extremist groups in Dagestan and Ingushetia so far this year.
"Things have been growing worse in the north Caucasus lately, but this is really the continuation of a threat we've been experiencing for the past 11 years," says Yulia Latynina, an investigative journalist who closely follows security issues. "Russia is the target of the international jihadist movement, but our state is less able to cope than many other countries."
'Black widows': an increasingly favorite tool of insurgents
Ms. Latynina says the female suicide bombers, who call themselves shakhidy, or martyrs, but have been dubbed "black widows" by Russian security forces, are an increasingly favorite tool of the insurgents. "By nationality, these shakhidy can be anything, even Russians," she says. "But by ideology they are Wahhabi [Muslim extremists], and they are not a new threat to be seen in Moscow."
Moscow was the scene of a wave of terrorist attacks soon after Russian troops invaded the separatist republic of Chechnya, for the second time, a decade ago. A still unsolved wave of apartment bombings in the autumn of 1999 killed almost 300 people. In subsequent years, over 1,000 Russians died in terrorist strikes, including a siege of a downtown Moscow theater in 2002 and a series of bombings in Moscow markets, Metro stations, and airliners.
But after Russian troops pacified rebel Chechnya the Kremlin declared victory, and a five year hiatus in terrorist attacks against Russia's heartland appeared to confirm the efficacy of then-President Vladimir Putin's tough measures.
But the bombing of a luxury train, crowded with officials, between Moscow and St. Petersburg last November had many experts warning that terrorists may be once again eyeing civilian targets in Russia's heartland and developing new tactics of attack.
"Bandit underground activity is still on, so they wanted to prove once more that they still exist and they are active," says Sergei Goncharov, head of a special services veteran's group. "This surely comes from the north Caucasus, which is a wound for Russia that cannot be healed."