ISIS behind brutal Moscow terror attack, France tells Russia, as Kremlin points to Ukraine

MOSCOW ? France on Monday joined the U.S. in saying intelligence shows the Islamic State was responsible for a grisly attack on a concert hall outside Moscow that killed 137 people ? while Russia continued to suggest Ukraine was to blame.

In the deadliest attack inside Russia for two decades, four men burst into the Crocus City Hall on Friday night, spraying people with bullets during a concert by the Soviet-era rock group Picnic. More than 180 people were wounded.

Four men, at least one a Tajik, were in custody on terrorism charges. They appeared separately, led into a cage at Moscow's Basmanny district court by Federal Security Service officers.

The Islamic State has claimed responsibility for the attack, a claim that the United States has publicly said it believes, and the militant group has since released what it says is footage from the attack. U.S. officials said they had warned Russia of intelligence earlier this month about an imminent attack.

"The information available to us … as well as to our main partners, indicates indeed that it was an entity of the Islamic State which instigated this attack," French President Emmanuel Macron told reporters, referring to Islamic State's affiliate in Afghanistan, which is known as ISIS-Khorasan, or ISIS-K.

"This group also tried to commit several actions on our own soil," he said during a visit to French Guiana.

France raised its terror alert warning to its highest level on Sunday after the shootings in Moscow.

WATCH: Moscow concert hall rampage leaves dozens dead, missing

Putin ignores ISIS, leans into 'the Ukrainian side'

President Vladimir Putin has not publicly mentioned the Islamist militant group in connection with the attackers, who he said had been trying to escape to Ukraine.

Putin said some people on "the Ukrainian side" had been prepared to spirit the gunmen across the border. Ukraine has denied any role in the attack, and President Volodymyr Zelenskyy has accused Putin of seeking to divert blame for the attack by mentioning Ukraine, something Macron said was a mistake.

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"I think that it would be both cynical and counterproductive for Russia itself and the security of its citizens to use this context to try and turn it against Ukraine," Macron said, adding that France had offered cooperation to help find the culprits.

Russia's Foreign Ministry spokeswoman, Maria Zakharova, earlier called into question U.S. assertions that the Islamic State, which once sought control over swathes of Iraq and Syria, was behind the attack.

In an article for the newspaper Komsomolskaya Pravda, she said the U.S. was evoking the "bogeyman" of Islamic State to cover its "wards" in Kyiv, and it reminded readers that Washington had supported the "mujahideen" fighters who fought Soviet forces in the 1980s.

Two U.S. officials said Friday that the United States had intelligence confirming Islamic State's claim of responsibility.

Kremlin spokesman Dmitry Peskov told reporters that Russia could not comment on the Islamic State claim while the investigation was ongoing and would not comment on the U.S. intelligence, saying it was sensitive information.

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Signs of torture

Putin said 11 people had been detained, including the four suspected gunmen, who he said had fled the concert hall and made their way to the Bryansk region, about 210 miles southwest of Moscow, to slip across the border to Ukraine.

Unverified videos of the suspects' interrogations circulated on social media. One of the suspects was shown having part of his ear cut off and stuffed into his mouth.

One man, a Tajik named Dalerdzhon Mirzoyev, leaned against the glass cage as the terrorism charge was read out. Saidakrami Rachabalizoda, his ear in bandages, remained sitting.

Muhammadsobir Fayzov, appeared in gaping hospital clothes sitting in a medical chair, his face covered in cuts. Shamsiddin Fariduni, his face bruised, stood.

The Kremlin's Peskov left a journalist's question about the treatment of the detainees unanswered.

Putin ordered a full-scale invasion of Ukraine in February 2022, triggering a major European war after eight years of conflict in eastern Ukraine between Ukrainian forces on one side and pro-Russian Ukrainians and Russian proxies on the other.

The U.S. and its European allies have supported Ukraine, extending billions of dollars in money, weapons and intelligence in a bid to defeat Russian forces.

This article originally appeared on USA TODAY: Moscow concert hall attack: France and U.S. say ISIS killed 137 people