A notorious Chechen rebel leader has claimed responsibility for ordering the twin suicide attacks on Moscow's subway system this week that left 39 people dead and he warned that more attacks are on the way.
In a video posted online tonight, Doku Umarov boasted that "these two operations were done on my order and they're not the last ones, inshallah," using the Arabic for "God willing."
Umarov, the self-proclaimed Emir of the Caucasus Emirate, said the attacks were in response to an operation by Russia's security services in February that killed 18 insurgents in the North Caucasus republic of Ingushetia.
"They were cruelly killed by these bandits who are called FSB [Russia's Federal Security Services]," he says.
"Soon you will see and hear another operation in response to those mujahedeen who died on February 11th," he finishes. "War will come to your streets, inshallah, and you will feel it with your own lives and skin."
Earlier today, two suicide bombers attacked police in the southern Russian republic of Dagestan, killing at least 12 people and injuring 27.
Two traffic policemen in Dagestan's town of Kizlyar were killed when they tried to stop a car driven by a suicide bomber. Twenty minutes later, a second bomber dressed as a police officer detonated his explosives at the site of the first blast as investigators inspected the wreckage. The local police chief was among the victims.
Authorities in the North Caucasus region of Russia are a frequent target of Islamic insurgents who have been fighting for decades for a separate Muslim state. There has been a spate of attacks in Dagestan, Ingushetia and neighboring Chechnya the past year as Russia struggles to quash the insurgency.
Umarov did not claim responsibility for today's attack but Prime Minister Vladimir Putin said he did not rule out that the same terrorist group could be behind both.
President Dmitry Medvedev called this week's two attacks "links of the same chain."
"All this is the manifestation of the same terrorist activity which has recently started to resurface in the Caucasus," Medvedev told the Russian Security Council.
Shortly after Monday's subway bombing, North Caucasus rebels were almost immediately suspected. The suicide bombers were both women, fueling speculation that a group of Chechen female suicide bombers known as the "Black Widows" who carried out several deadly attacks earlier this decade has been revived.
The Kommersant newspaper reported that the FSB is now looking for a group of "Black Widows" still at large.
FSB sources told the newspaper that 30 women bombers had been trained in Turkey and Russia under the tutelage of Said Buryatsky, a rebel leader killed in an FSB sweep earlier this month. Of the 30, nine have made attacks so far, with 21 reportedly still on the loose.
There was immediate speculation that Umarov was involved with Monday's suicide bombings since he had claimed responsibility for Russia's last big attack, the bombing of an express train between Moscow and St. Petersburg that killed 26.
Umarov warned in a video in February that "war is coming to [Russian] cities."
Today's four and a half minute video, posted on the same website where Umarov has made past statements, repeatedly warned that "this is not the last operation," and that they will continue "on your territory."
Before the video was released, Reuters quoted an alleged Umarov spokesman who denied responsibility for Monday's attack.
There has been significant concern that violence in the North Caucasus, often ignored by Russians and the press, will spill over into the rest of Russia.
"I'm very afraid it could be part of a new round, the next round of terrorism not just in the Caucuses but in Russia itself," Alexei Malashenko, an expert on the North Caucasus at the Carnegie Moscow Center, told ABC News.
"Radical extremists have accumulated forces, they had a good experience [on Monday], there's a new generation between 20 and 25 years old. I think they'll do something," he added.
Photos have emerged on Russian Web sites allegedly showing the faces of the Monday's female bombers as well as a frame of video of a goateed man suspected of shepherding the them to Moscow by bus from the North Caucasus. Russia's Interior Ministry has circulated pictures of the man and two female accomplices to police, but they did release them to the public and refused to comment on the veracity of the photos circulating online.
Security forces are on alert in both Moscow and Dagestan have been put on alert. The police presence in the Moscow subway has multiplied and cameras have been added to boost surveillance. On Wednesday, Medvedev ordered steps to be taken to develop a "complex system to guarantee security" on the country's public transportation.
It is unclear how Russia will respond to a potentially growing threat emanating from its south. While he was president, Putin advocated an iron-fisted approach and on Tuesday called for those responsible to be "scraped from the sewers."
Medvedev has also called for the terrorists to be "destroyed" but he has encouraged using social and economic efforts to quell the violence.
"I think it's necessary to keep the previous political course of reconciliation, economic reforms and the amelioration of living standards," said Malashenko. "If they continue to press, send additional forces to kill people, that will be a big mistake."
On Wednesday night, 3,000 people gathered at Moscow's Lubyanka metro station – the site of the first blast Monday – to pay their respects, a police official told Interfax.