Many questions remain after Moscow terror attack leaves dozens dead

Russian security officials were seeking suspects and motives a day after the terrorist attack that left at least 133 people dead at a concert hall near Moscow, the authorities said on Saturday, after making initial arrests.

The Daesh (ISIS) terrorist militia published pixilated photos of the alleged attackers on Saturday, after claiming responsibility for the attack on the Crocus City Hall concert venue.

However, Russian President Vladimir Putin said a "trail" suggested Ukraine was behind Friday's attack, following the arrest of several men, accusations Kiev swiftly rejected.

Shortly before the start of a concert on Friday evening, unidentified men wearing camouflage clothing stormed the concert hall in the north-western Moscow suburb of Krasnogorsk and opened fire on the crowd, the Prosecutor General's Office said.

Perpetrators shot indiscriminately at visitors, eyewitnesses said. There were also explosions in the building and a major fire that collapsed the roof.

As hospitals took in scores of people who were injured, the authorities called for blood donations, setting up centres for this purpose.

On Saturday, hundreds of mourners lined up to commemorate the victims of the attack, laying flowers and lighting candles at the site.

Three children were among those killed and local residents also placed toys near the hall, as emergency workers continue to clear the rubble and search for further victims.

Eleven suspects have been detained, at least four of whom were directly involved in the attack on the event centre, according to the head of the FSB security service Alexander Bortnikov. The arrests were made in the Bryansk border area, a region to the south-west of Moscow bordering Ukraine and Belarus, the FSB said earlier.

Officials continue their search for suspects.

In a televised address to the nation on Saturday afternoon, Putin claimed that the four perpetrators were arrested on their way to an escape route into Ukraine.

Ukraine's military intelligence service dismissed Putin's assertion, pointing out that the border has long been mined in light of Russia's full-scale invasion of Ukraine launched in February 2022, and that the border area is full of Russian troops, special agents, intelligence services and security forces, making it an unlikely escape route for the attackers.

But despite the Daesh claim of the attack, which the Kremlin has so far not commented on though it is seen as genuine by security experts, many questions remain.

Western and US intelligence services warned an attack might be imminent at the start of the month, with the US embassy in Moscow calling on citizens to avoid large gatherings, having seen reports that extremists were planning to attack large gatherings in the Russian capital, including concerts.

Putin dismissed the warnings as Western provocations aiming to destabilize Russia, in a speech to the FSB earlier in the week.

Daesh mouthpiece Amaq Agency published a picture of four people with armed with assault rifles, pistols and bombs. The fighters, who could not be recognized, caused "great destruction," the agency said.

Daesh fights followers of Christianity and considers them to be infidels.

Russia is fighting Daesh in Syria and the terrorist militia has often criticized Russia's military deployment, security specialists have said.

Russian investigators have not commented on the statements on Amak. There were unconfirmed reports that the suspects were Tajik citizens, but the passports found in their getaway car may not be genuine.

Leaders around the world condemned the attack and expressed sympathy and support for the victims and their families, including US Secretary of State Antony Blinken, French President Emmanuel Macron and German Chancellor Olaf Scholz.

Friday's attack was a "heinous crime," US Secretary of State Antony Blinken said on Saturday.

Residents of Beslan, the North Caucasus city that saw one of the deadliest school shootings in history some 20 years ago, also commemorated the victims of the Moscow attack.

The victims were said to be both employees and visitors to the concert hall, where Russian rock band Piknik was due to perform.

The centre is one of the most popular event centres in the capital, hosting concerts, trade fairs and exhibitions.

Putin ordered a national day of mourning on Sunday. All theatres, cinemas and museums in Moscow are closed for the weekend.