Russia mourns after worst terrorist attack in decades; here are latest updates

Russia is grappling with the aftermath of its most severe terrorist attack in decades. Gunmen stormed into a concert hall in Moscow on March 23 and started randomly shooting people who had gathered for a show by rock group Picnic. They also threw grenades or incendiary bombs.

The attack lasted about 20 minutes and nearly 133 have been killed and several injured.

Nearly 11 individuals have been apprehended, including four, who were directly involved in the massacre.

Here's the latest information available:

According to the latest update from Russia’s Investigative Committee on Saturday, at least 133 people have been killed at the vast complex.

Many died from bullet wounds, some as a result of smoke inhalation. Scores of people hid behind seats in the hall or rushed towards entrances to the basement or roof to escape the bullets. The first official list of casualties suggested the oldest victim was in her 70s, with three children among the dead.

Authorities anticipate the death toll to rise as emergency responders continue working through the scene. In addition to those killed, at least 60 remain in a serious condition.

Three helicopters were involved in efforts to put out the fire, dumping water on the giant concert hall that can hold several thousand people and has hosted top international artists. . Shortly after midnight, the emergencies ministry said the fire had been contained.

Who are the attackers?

ISIS claimed responsibility and said that three fighters attacked the gathered crowd at the venue with guns and knives, while the fourth threw incendiary devices. It said the attack had taken place after an extensive surveillance operation of the place.

It added that “the attack comes within the normal context of the raging war between the Islamic State and countries fighting Islam.” Meanwhile, ISIS-affiliated news agency Amaq released a graphic video on Saturday that purports to show Friday’s attack in the concert hall was recorded by one of the attackers, suggesting the perpetrators had a direct link to ISIS in order to be able to send the video.

Meanwhile, Ukraine, which is fighting a war with Russia, denied any involvement in the massacre. The European Union, France, Spain and Italy joined several countries in condemning the attack. The US called the attack "terrible" and said there was no immediate sign of any link to the conflict in Ukraine.

Day of mourning

Russia is observing a day of mourning on Sunday for the more than 130 victims of the attack on a Moscow concert hall on Friday.

President Vladimir Putin vowed to punish the perpetrators and expressed condolences to those who had lost loved ones.

"The whole country, our whole people, mourns with you," he said. 

Putin had also denounced the terrorist killings as a "bloody and barbaric act" in a video statement issued on Saturday.

Even as Russia observed a day of national mourning on Sunday, family and friends of those still missing after the attack ware waiting for news of their loved ones.

Events at cultural institutions were cancelled, flags were lowered, and TV entertainment and ads were suspended, according to state news agency RIA Novosti. A steady stream of people brought flowers to a makeshift memorial near the burnt-out concert hall.

US warning

Meanwhile, the United States said it had warned Moscow that ISIS militants were determined to target Russia in the days preceding the assault on the concert hall. Two weeks before the attack the US said there was a risk of "extremists" targeting mass gatherings in Moscow, including concerts.

Putin, however, criticised the American warnings as "provocative," likening them to blackmail and an attempt to intimidate and destabilise Russian society.