Russian investigators have charged Chechen warlord Doku Umarov with organizing a deadly suicide bombing on Moscow's Domodedovo Airport that killed 37 people in January.
The announcement came a day after security forces claimed to have slain 17 Islamic rebels in the North Caucasus, where the Kremlin has been battling an Islamist insurgency for the past two decades.
A spokesman for the Investigative Committee of the Prosecutor-General's Office, Vladimir Markin, said the committee also decided to bring charges against another militant, Aslan Byutukayev.
Umarov, the leader of the North Caucasus insurgency and Russia's most-wanted man, claimed responsibility for masterminding the attack in an online video. He has also claimed responsibility for twin suicide bombings on Moscow's metro a year ago that killed 40 people.
Byutukayev, also known as Emir Khamzat, is believed to have trained suicide bombers for a number of attacks, including the one at Domodedovo Airport.
President Dmitry Medvedev praised the March 28 raid in the North Caucasus and said it had "dealt a heavy blow" to the insurgents.
Media reports, citing law-enforcement sources, said Umarov and Byutukayev may have been killed during the operation in Ingushetia, a small republic bordering Chechnya.
Russian officials, however, have prematurely announced Umarov's death on a number of occasions.
The clashes in the Ingush village of Verkhny Alkun included air strikes and were part of a large-scale counterinsurgency operation. Authorities said three law-enforcement officers died in the fighting.
Markin said two other insurgents were detained on March 28 on suspicion of helping Magomed Yevloyev, a 20-year-old man from Ingushetia, stage the attack at Domodedovo Airport.
"During the special operation currently being conducted on the territory of Ingushetia, two of the republic's residents, brothers Islam and Ilez Yandiyev, were also arrested," Markin said.
"According to the investigation, they were the ones who met the suicide terrorist Magomed Yevloyev in Moscow and who took him to Domodedovo Airport on January 24."
A suicide bomber's belt and two homemade bombing devices were reportedly found at the brothers' home.
Markin also said authorities had tracked down all seven perpetrators of last year's deadly subway bombings, six of whom were killed by security forces. He said an international warrant had been issued for the remaining militant.
Despite recent gains in the North Caucasus, the Kremlin faces an uphill battle in stamping out insurgents from the restive region.
Grinding poverty, compounded by corruption and abuse by security forces, has driven many young men to join the insurgency.
Aleksei Malashenko, a Caucasus expert at the Carnegie Center in Moscow, says the March 28 raid could actually stoke fresh violence.
"It was undeniably a success; security services must be given their due," Malashenko says. "But I don't think anything will come out of it because we've seen how slain militants are always replaced by new ones."
WATCH: Moscow residents brought flowers and candles to the Lubyanka and Park Kultury subway stations to remember the victims of two deadly blasts that occurred at the stations a year ago.
Muscovites, meanwhile, flocked to the site of the subway bombings today to pay their respects to victims on the first anniversary of the tragedy.
One woman in Moscow expressed what many were thinking. "I came here especially to observe a minute of silence for the innocent victims," she said. "This government is not protecting us from bandits. Every one of us can find oneself in this kind of tragic situation."
written by Claire Bigg, with reporting from RFE/RL's Russian Service