Russia has arrested 11 people including four suspected gunmen in connection with a shooting rampage that killed 93 people in a concert hall near Moscow, the Kremlin said on Saturday.

It said FSB security service 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.

Russia’s Investigative Committee said the death toll had leapt to 93 from the attack in which camouflage-clad gunmen opened fire with automatic weapons at concertgoers near the capital on Friday.

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.

Daesh has claimed responsibility for the attack, the deadliest in Russia since the Beslan school siege in 2004.

The shooting took place on Friday evening at Crocus City Hall, a concert venue just west of Moscow where a Soviet-era rock band was due to perform.

Verified video showed people taking their seats in the 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.

“A stampede began. Everyone ran to the escalator,” the witness said. “Everyone was screaming; everyone was running.”