A group of gunmen attacked a crowd of concert goers at the Crocus City Hall in western Moscow on the night of March 22, killing at least 40 and injuring up to a 100 more, according to the Federal Security Service (FSB).

There is no information on who the gunmen were. Video from those in the building show horrific scenes of half a dozen men walking through the building shooting civilians with Kalashnikov machine guns at point blank range. They were wearing military fatigues and assault vests with spare ammo and appear to be military trained. Other videos show the entrance to Crocus City, one of Moscow’s biggest shopping malls and concert halls, littered with bodies slumped on the floor or couches in the reception area.

The burning question of the moment is: who are the attackers?

Ukrainian presidential adviser Mykhailo Podolyak has already issued a statement on social media saying Ukraine had “nothing to do with Moscow shootings.” The White House has also issued a statement saying the same. The FSB has yet to comment.

It appears unlikely that the attackers were Ukrainians or connected to the war, as the targets in the attacks were Russian civilians, and that would be a departure from the few previous attacks by Ukrainians on Russian soil.

Ukraine has carried out terrorist-style slaughter in Russia since the start of the war. Journalist Darya Dugina, the daughter of famous philosopher and “Putin’s brain,” was killed by a car bomb in August 2022 in an attack ascribed to Kyiv. The White House was reportedly very angry with Kyiv for carrying out a terrorist-style murder on Russian soil, afraid of reprisals.

Then Russian military blogger Vladlen Tatarsky was also killed by a bomb blast in a St Petersburg cafe in April last year in another terrorist-style attack.

But in both these cases, the killings were very clearly connected to the war in Ukraine, as both were prominent media figures who were advocating attacks on Ukraine (assuming that the real target for Darya Dugina death was her father Alexander).

The targets in the Crocus Hall attacks were normal Russians who were on a night out and were not highly planned and targeted killings, unlike the two earlier assassinations. Innocent victims were simply mowed down at random where they stood by the Crocus City shooters.

It's still too early to be sure about anything, but the Crocus City attacks have much more in common with Russia’s two major post-Soviet terrorist attacks: the Nord Ost theatre hostage siege in 2002 and the Beslan school siege in 2004.

In October 2002 a small group of heavily armed Chechen fighters took control of the theatre in suburban Moscow and held hundreds hostage for days before the building was finally stormed and the Chechens gassed and then shot.

Like Crocus City, Nord Ost was full of regular Russians on a night out. Like Crocus City, the gunmen were a small group of well-armed fighters, wearing the same sort of military fatigues and carrying the same sort of arms and grenades.

I covered that story for the Daily Telegraph when I was Moscow correspondent in 2002. For four days we stood with the relatives of the hostages in a cordoned-off zone outside the theatre waiting for news. Occasionally there was some shooting as the Chechens traded shots with the special forces, or occasionally a grenade would go off. I went home to catch a few hours of sleep each day, but eventually the Alfa forces stormed the build at 4am and all hell broke loose.

The same is true of Beslan, although there the group of attackers was larger and probably better armed. They attacked a school rather than a theatre, but that was likewise filled with innocents.

The very first attack on Russian soil was the much less publicised Budyonnovsk hospital hostage crisis, when group of heavily armed Chechen warriors seized a hospital in June 1995 just across the border into Russia during the first Chechen war led by infamous Chechen commander Shamil Basayev. Those hostages escaped with their lives, but the point is, there is a very long tradition of Russian terrorists targeting civilians in theatres, schools and hospitals.

At Nord Ost the FSB came up with an innovative solution of using a powerful narcotic gas that knocked everyone out in minutes, something that Mossad, who was advising the FSB during the siege, had never thought of before. In the end the plan backfired as the FSB refused to tell the doctors receiving the unconscious hostages what kind of gas they had used and well over a hundred hostages overdosed on the gas and died.

The end of the Beslan siege was even more tragic as tensions were extremely high and shooting broke out that quickly turned into a firefight in which dozens of children were shot and killed in the crossfire.

Given this history of bloody ends to terror sieges, if the attackers were domestic then they would be well aware that taking hostages will not protect you from a reprisal from the Russian special forces. That may have encouraged the indiscriminate shooting and the fact that the gunmen appear to have escaped.

If the Crocus City shooting was a domestic terrorist attack, then it is the first serious attack since Putin’s first term in office twenty years ago. He came to power talking tough after a series of apartment bombs in 1999 killed hundreds of Russians asleep in their beds – bombings that Putin himself have been accused of organising as part of a plan to get him elected president. Then Russia was plunged into the second Chechen war, which Putin ruthlessly crushed by bombing the Chechen capital Grozny flat.

But over the course of the next decade Putin stamped the insurgency out. He made Ramzan Kadyrov president of Chechnya, who was a former freedom fighter against the Russian forces and is the son of former Chechen President Akhmad Kadyrov, who switched sides in the second war by offering his service to Putin's administration. He became Chechen president in 2003 but was assassinated by a bomb buried in the cement of a football stadium under his chair.

Ramzan Kadyrov has been a loyal Putin servant ever since and is a poacher turned gamekeeper, who has kept a lid tightly on Chechen terrorism ever since.

However, Putin has made few friends in the poorer parts of the Russian federation in the last two years. The partial mobilisation of September 2022 almost exclusively targeted the ethnic minorities in regions like Dagestan in the Caucasus, where there were large-scale demonstrations that were brutally disbursed by the local authorities, while the more prosperous (and largely Slavic) European regions were left more or less untouched.

It could be that this blatant use of Russia’s ethnic minorities to provide the cannon fodder has touched a fuse that has reignited Russia’s terrorism again, but it is still too early to say. In the meantime, Moscow is in shock, as it hasn’t seen a terrorist act on this scale or ferocity for at least two decades.