At least 60 people were massacred and 145 others were wounded after several gunmen opened fire during a concert in Moscow on Friday, according to Russian officials.

ISIS claimed responsibility for the attack in a brief statement posted on Telegram on its affiliated news agency Amaq. The terrorist group did not provide any evidence to substantiate their claim.

Disturbing video posted online showed gunmen in military uniforms shooting screaming civilians with automatic weapons as others ducked for cover at the Crocus City Hall, where Russian rock band Picnic was about to take the stage for a sold-out show.

Other footage shows the men firing at concertgoers at point-blank range below the venue’s entrance sign as bloodied bodies lay motionless on the ground.

Russian media reports said that the assailants threw explosives, triggering the massive blaze at the hall, which can hold 6,200 people. Video showed flames and black smoke light up the night sky as scores of ambulances, fire trucks and riot police flocked to the chaotic scene. 

Helicopters dropped water on the building as responders evacuated around 100 people from the basement, Russian media reported. The fire caused the venue’s roof to collapse.

Russia’s Investigative Committee, the top state criminal investigation agency, confirmed that more than 60 people were killed. Another 145 were injured, of which 115 victims — including five children — were hospitalized. 

“Unfortunately, the number of victims may increase,” the agency said in a statement.

Law enforcement officials said several men in combat fatigues entered the concert hall and fired on concertgoers.

“Suddenly there were bangs behind us — shots. A burst of firing — I do not know what,” one witness who asked not to be named told Reuters.

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

Volleys of gunfire can be heard ringing out repeatedly in videos posted by Russian media. None of the venue’s security guards had guns and may be among those who were killed, according to reports.

It was not immediately clear what happened to the attackers. Some Russian outlets reported they fled before special forces and riot police arrived.

A US intelligence official, speaking on condition of anonymity, told the Associated Press that US intelligence agencies had learned ISIS’ Afghanistan branch was planning an attack in Moscow and privately shared the information with Russian officials earlier this month.

On March 7, the US Embassy in Moscow warned American citizens about the threat of terrorist attacks in Moscow — specifically at concerts.

“The Embassy is monitoring reports that extremists have imminent plans to target large gatherings in Moscow, to include concerts, and US citizens should be advised to avoid large gatherings over the next 48 hours,” the embassy said at the time.

Just three days ago, Russian President Vladimir Putin accused the West of making “provocative statements” about potential terror attacks in Russia. He dismissed them in remarks aired on Russian media, NBC News reported.

“I’ll remind you of recent, let’s say directly, provocative statements of certain official Western structures about potential terror attacks in Russia,” Putin said.

“All of this looks like obvious blackmail and an attempt to intimidate, destabilize our country,” he said before the Russian security agency FSB.

ISIS bombed a Russian passenger plane over Egypt in Oct. 2015, killing all 224 on board, most of whom were Russians returning from vacation.

The terrorist group, which still operates in Syria and Iraq with branches in other countries, has claimed credit for a number of violent attacks in Russia’s Caucasus and other regions over the years.

On March 7, Russia’s top security agency said it stopped an attack on a Moscow synagogue planned by an ISIS cell. Authorities killed several members in the Kaluga region outside of the capital.

A few days earlier, Russian authorities claimed six alleged ISIS members were killed in a shootout in Ingushetia in Russia’s Caucasus region.

The mass shooting is one of the deadliest attacks in Russia in years. Russia’s foreign ministry called it a “bloody terrorist attack.”

“The entire world community is obliged to condemn this monstrous crime,” Foreign Ministry Spokeswoman Maria Zakharova said. “All efforts are being thrown at saving people.”

White House National Security Adviser John Kirby called the videos and images from the attack “hard to watch.”

“Our thoughts are going to be with the victims of this terrible, terrible shooting attack,” Kirby said. “There are some moms and dads and brothers and sisters and sons and daughters who haven’t gotten the news yet. This is going to be a tough day.”

Kirby said there was “no indication at this time that Ukraine, or Ukrainians were involved in the shooting.”

Zakharova demanded to know how the US could know Ukraine was not involved. She said Washington should immediately pass any information it had to Moscow — or stop making such statements.

“On what basis do officials in Washington draw any conclusions in the midst of a tragedy about someone’s innocence?” Zakharova said.

Kirby told reporters that he does not believe the embassy’s warning earlier this month was related to Friday’s attack. When asked if the US had any prior information about the assault, Kirby said he is “not aware of any advance knowledge that we had of this terrible attack.”

Ukrainian presidential adviser Mykhailo Podolyak claimed Kyiv “had absolutely nothing to do with these events” in a video message posted on Telegram.

Hours before the attack, the Russian military paralyzed Ukraine’s electrical grid after targeting power sources, leaving more than a million people without power.

Security at Moscow’s airports and railways stations was tightened in response to the shooting. All mass gatherings have been canceled for the weekend in the capital city, the mayor announced.

“A terrible tragedy occurred in the shopping center Crocus City today,” Moscow Mayor Sergei Sobyanin said. “I am sorry for the loved ones of the victims.”

The attack comes just days after Putin secured his grip on the country for another six years in a landslide election victory.

The Kremlin said Putin is aware of Friday’s attack.

“The president constantly receives information about what is happening and about the measures being taken through all relevant services. The head of state gave all the necessary instructions,” spokesperson Dmitry Peskov said.

With Post Wires