Russia has arrested 11 people including four suspected gunmen in connection with a shooting rampage that killed at least 115 people in a concert hall near Moscow, the Kremlin said on Saturday.
Militant group Daesh claimed responsibility for Friday's attack, the deadliest in Russia for 20 years. But there were indications that Russia was pursuing a Ukrainian link, despite a statement from Ukrainian presidential adviser Mykhailo Podolyak that Kyiv had nothing to do with it.
The FSB security service said "all four terrorists" had been arrested while heading to the Ukrainian border, and that they had contacts in Ukraine. It said they were being transferred to Moscow.
"Now we know in which country these bloody bastards planned to hide from pursuit - Ukraine," Foreign Ministry spokeswoman Maria Zakharova said on Telegram.
Death toll soars
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.
Russia's Investigative Committee said the death toll had leapt to at least 115 from the attack, in which camouflage-clad gunmen opened fire with automatic weapons at concertgoers in the Crocus City Hall near the capital
It 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.
Identify accomplices
The Kremlin said FSB chief Alexander Bortnikov had reported to President Vladimir Putin that those detained included "four terrorists" and that the service was working to identify their accomplices.
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 and disobeyed instructions to stop.
He said two were arrested after a car chase and two others fled into a forest. From the Kremlin account, it appeared they too were later detained.
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.
Rushing for exits
Verified video showed people taking their seats in the concert hall, then rushing for the exits as repeated gunfire echoed above screams. Other video showed men shooting at groups of people. Some victims lay motionless in pools of blood.
"Suddenly there were bangs behind us - shots. A burst of firing - I do not know what," one witness, who asked not to be identified by name, told Reuters.
Long lines formed in Moscow on Saturday for people to donate blood. Health officials said more than 120 people were wounded.
"The death toll is expected to rise," the Investigative Committee, which handles major crimes in Russia, said on Telegram.
The Moscow city and regional governments said they would provide financial support for families of the victims and those injured, as well as paying for funerals.
The militant group Daesh that once sought control over swathes of Iraq and Syria, claimed responsibility for the attack, the group's Amaq agency said on Telegram.
It 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.
World reaction
Russian Foreign Ministry spokeswoman Zakharova said it was a "bloody terrorist attack" that the world should condemn.
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 over 21 million people. All large-scale public events were cancelled across the country.
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