Islamic State released on Saturday a photo of what it said were the four attackers behind a shooting rampage that killed at least 143 people in a concert hall near Moscow on Friday, the terrorist group's Amaq news agency said on Telegram.
The publication noted that the attackers were armed with grenades, explosive devices, firearms, and knives. It was also reported that four ISIS terrorists carried out the attack - three of them were firing shots with firearms, while the fourth used explosives at the scene, Ynet reported.
"The attack comes within the context of a raging war between the Islamic State and countries fighting Islam," Amaq added in a statement citing security sources.
Islamic State claimed responsibility for the attack but there were indications that Russia was pursuing a Ukrainian link, despite empathic denials from Ukrainian officials that Kyiv had anything to do with it.
Russian authorities said on Saturday they had arrested 11 people including four suspected gunmen in connection with the attack.
Although US officials have confirmed to several media outlets that ISIS is behind the attack, Russia's Federal Security Service (FSB) insists that the terrorists have ties to Ukraine.
Putin addressed the nation
Putin cast the enemy as "international terrorism" and said that he was ready to work with any state that wanted to defeat it.
"All the perpetrators, organizers and those who ordered this crime will be justly and inevitably punished. Whoever they are, whoever is guiding them," Putin said. "We will identify and punish everyone who stands behind the terrorists, who prepared this atrocity, this strike against Russia, against our people."
A senior Russian lawmaker, Andrei Kartapolov, said that if Ukraine was involved, then Russia must deliver a "worthy, clear and concrete" reply on the battlefield.
Verified footage from Friday's attack showed camouflage-clad gunmen opening fire with automatic weapons at concert-goers in the Crocus City Hall near the capital. Video showed people taking their seats, then rushing for the exits as repeated gunfire echoed above screams.
Investigators said some died from gunshot wounds and others in a huge fire that broke out in the complex. Reports said the gunmen had lit the blaze using petrol from canisters they carried in rucksacks.
People fled in panic. Baza, a news outlet with good contacts in Russian security and law enforcement, said 28 bodies were found in a toilet and 14 on a staircase. "Many mothers were found embracing their children," it said.
Russian lawmaker Alexander Khinshtein said the attackers had fled in a Renault vehicle that was spotted by police in Bryansk region, about 340 km (210 miles) southwest of Moscow on Friday night. He said a car chase ensued after they disobeyed orders to stop.
Khinshtein said a pistol, a magazine for an assault rifle, and passports from Tajikistan were found in the car. Tajikistan is a mainly Muslim Central Asian state that used to be part of the Soviet Union.
A suspect was interrogated
TV editor Simonyan published a video showing one of the suspects, a young, bearded man, being interrogated aggressively by a roadside, replying in heavily accented Russian to a series of barked questions. He said he had flown from Turkey on March 4 and had received instructions from unknown people via Telegram to carry out the attack in exchange for money.
The man was trembling throughout the questioning. He was initially shown lying on his stomach with his hands bound behind his back, his chin resting on the boot of a figure in camouflage uniform. Later he was hauled up onto his knees.
Another man with cuts and bruises to his face was shown being questioned via an interpreter while sitting on a bench with bound hands and feet.
The Kremlin said Putin had held conversations with the leaders of Belarus, Uzbekistan and Kazakhstan in which all sides affirmed their willingness to work together to fight terrorism.
Citizens donating blood
Long lines formed in Moscow on Saturday for people to donate blood. Health officials said more than 120 people were wounded.
Islamic State, the terrorist group that once sought control over swathes of Iraq and Syria, claimed responsibility for the attack, the group's Amaq agency said on Telegram.
Islamic State said its fighters attacked on the outskirts of Moscow, "killing and wounding hundreds and causing great destruction to the place before they withdrew to their bases safely." The statement gave no further detail.
The United States has intelligence confirming Islamic State's claim of responsibility for the shooting, a US official said. The official, speaking on condition of anonymity said Washington had warned Moscow "appropriately" in recent weeks of the possibility of an attack.
Friday's attack, about 20 km (12 miles) from the Kremlin, happened two weeks after the US embassy in Russia warned that "extremists" had imminent plans for an attack in Moscow.
ISIS-Khorasan
Hours before the embassy warning, the FSB said it had foiled an attack on a Moscow synagogue by Islamic State's affiliate in Afghanistan, known as ISIS-Khorasan or ISIS-K, which seeks a caliphate across Afghanistan, Pakistan, Turkmenistan, Tajikistan, Uzbekistan and Iran.
Putin changed the course of the Syrian civil war by intervening in 2015, supporting President Bashar al-Assad against the opposition and Islamic State.
ISIS-K is named after an old term for the region that included parts of Iran, Turkmenistan and Afghanistan, emerged in eastern Afghanistan in late 2014 and quickly established a reputation for extreme brutality. It has seen its membership decline since peaking around 2018.
The group's attacks include twin bombings in Iran that killed nearly 100 people. Additionally, in September 2022, ISIS-K claimed responsibility for a deadly suicide bombing at the Russian embassy in Kabul.
The group was also responsible for an attack on Kabul's international airport in 2021 that killed 13 US troops and scores of civilians during the chaotic US evacuation from the country.
"ISIS-K has been fixated on Russia for the past two years, frequently criticizing Putin in its propaganda," said Colin Clarke of the Soufan Center, a New York-based research group.
The broader Islamic State group has claimed deadly attacks across the Middle East, Afghanistan, Pakistan, Iran, Europe, the Philippines, and Sri Lanka.
The United States, European and Arab powers and many former Soviet republics expressed shock and sent their condolences. The United Nations Security Council condemned what it called a "heinous and cowardly terrorist attack."
Russia tightened security at airports, transport hubs and across the capital - a vast urban area of more than 21 million people - and big public events were canceled across the country.