The service had previously stated that the death toll was 93, but later issued an update announcing that more bodies were found after the emergency services started clearing the rubble.

'According to preliminary data, the causes of death were gunshot wounds and poisoning by combustion products (smoke inhalation),' investigators said, adding that they are continuing to establish all the details of the attack by analyzing evidence at the scene, going through CCTV footage, and taking statements from the victims.

The Moscow Region Health Ministry had also previously reported that there were at least three children among the deceased.

The tragic events unfolded on Friday evening at the Crocus City Hall in Krasnogorsk, on the western outskirts of the Russian capital. The concert venue, with an estimated capacity of 7,500, was almost full when the terrorists struck. The assault took place ahead of a performance by the Russian rock band Picnic.

Judging by mobile phone footage and eyewitness accounts, at least five gunmen wearing military-style gear and carrying assault rifles first opened fire at unarmed security guards at the main entrance to the venue. They then proceeded to shoot indiscriminately at the fleeing crowd of panicked visitors.

Once the terrorists reached the concert hall, they appeared to set fire to rows of chairs inside, with the blaze quickly engulfing much of the building, including the roof.

Investigators have stated that preliminary findings based on evidence at the scene appear to confirm that the terrorists used automatic weapons during the attack, and used some sort of flammable liquid to set fire to the premises.

The Investigative Committee said it is now carrying out ballistic, genetic, and fingerprint analyses based on the material evidence found at the scene.

Russia's Federal Security Service (FSB) has reported that eleven suspects, including four terrorists who directly took part in the Crocus attack, have been detained. The service noted that the attackers were apprehended as they were trying to make their way to the Ukrainian border.

Photo © Sputnik Image © Evgeny Biyatov/Sputnik

Crocus death toll rises to 115 - investigators