BOULDER – At least six people marching in support of Israeli hostages held in Gaza were burned on Sunday by a man wielding what authorities called a “makeshift flamethrower” and an incendiary device.

The attack happened just before 1:30 p.m. on Boulder’s Pearl Street Mall, during a walk organized by the city’s chapter of “Run for Their Lives,” which calls for the release of hostages held in Gaza by the terrorist group Hamas.

Mark Michalek, special agent in charge of the FBI’s Denver field office, characterized the incident as a “targeted act of violence” and said it’s under investigation as terrorism in a Sunday evening news briefing, echoing a statement from FBI Director Kash Patel earlier that day.

Mohamed Sabry Soliman, a 45-year-old man whom bystanders pointed out to police officers outside the Boulder County Historic Courthouse, was arrested, Michalek said.

Soliman used a makeshift flamethrower and threw incendiary devices into the crowd gathered outside the courthouse to harm them, Michalek said, saying the man yelled “Free Palestine” during the attack.

Videos show people rushing to pour water on one victim while others lay collapsed nearby.

“It’s almost like it was a gun of fire,” said Lynn Segal, who witnessed the attack. “It’s like a line of fire.”

The six victims were between the ages of 67 and 88, Michalek said. Four were taken to the Boulder Community Health hospital and two were airlifted to the University of Colorado’s burn unit in Aurora with more severe injuries.

Police arrested a shirtless man at the scene, who was shown in videos posted to social media holding glass bottles and shouting “Free Palestine” and calling to “end Zionists.”

Asked about Soliman’s affiliations with any other groups, Boulder Police Chief Stephen Readfearn said the investigation – which includes the FBI – was ongoing, though he said authorities were almost certain that the suspect acted alone. He said Soliman sustained minor injuries and was treated at an area hospital.

Few details were available about Soliman late Sunday night. He does not appear to have any presence on social media – an Egypt-based fashion influencer with the same name does not match the person caught on video by witnesses – and he does not have a criminal record in Colorado, court records show.

A spokesperson for U.S. Immigration and Customs Enforcement could not be reached for comment on Soliman’s immigration status.

“Boulder is not immune to tragedy, sadly,” Redfearn said. “I know a lot of people are scared right now, a lot of people are upset and questioning how this happened and why. All I know Boulder has recovered before from acts of violence, and we will again recover.”

Johanna Schmidt, whose parents regularly participated in the Boulder walks held by the organization, said she was on the way to the event with her children when her mother called and told her that someone had thrown a Molotov cocktail at the group and that Schmidt’s father had been burned.

Molotov cocktails are typically bottles filled with gasoline or alcohol that are then ignited and thrown.

Schmidt said the scene was “chaotic,” “absolutely horrific and shocking.” Her father sustained a second-degree burn and was released from the hospital Sunday evening.

Videos posted to social media show a woman lying on the ground while people pour water on her, as smoke and screams erupt from the area. Another video shows the shirtless man holding the bottles and shouting. In the background, bystanders can be seen huddled over someone on the ground.

“He’s right there, he’s throwing Molotov cocktails right there,” one person can be heard saying to police in one video. Police then handcuffed the man near the fountain in front of Boulder’s courthouse.

Later, a Reddit user posted photos and videos of a woman with a burned leg sitting on the lawn with paramedics, another person being loaded onto a stretcher, and people gathered in front of the building, now blocked with crime tape.

In a statement, Run for Their Lives said its “greatest concern at this moment is the well-being of the members of our group, most especially those who have been hospitalized.”

“We are dedicated to our mission that this is an international humanitarian crisis and that no one should ever be taken hostage and kept underground in tunnels without basic humanitarian needs and aid,” the group wrote.

In a statement Sunday, Gov. Jared Polis, who lives in Boulder, called the attack a “heinous act of terror.” National Jewish organizations condemned the attack and linked it to other recent violence that’s unfolded in the United States in response to the war in Gaza, including the killing of two Israeli embassy staff members in Washington, D.C., and the fire that tore through the residence of Pennsylvania Gov. Josh Shapiro, who is Jewish.

World Jewish Congress President Ronald S. Lauder said in a statement the Boulder attack was part of a “broader wave of hate.”

“It is not just the Jewish community that suffers,” Lauder wrote. “This violence tears at the very fabric of our societies. We call on law enforcement and government leaders – at every level, in every state, in every country – to act decisively.”

Israel’s campaign in Gaza began when Hamas-led militants stormed into southern Israel on Oct. 7, 2023, killing some 1,200 people, mostly civilians, and abducting about 250 others. The group still holds 58 hostages — which Sunday’s walk was meant to protest. Around a third of the hostages are believed to be alive, after most of the rest were released in ceasefire agreements or other deals.

Israel’s military campaign has killed over 54,000 people in Gaza, mostly women and children, according to Gaza’s Health Ministry. The offensive has destroyed vast areas, displaced around 90% of the population and left people almost completely reliant on international aid.

Horrified and enraged

Xale Chartier was heading to a downtown parking structure when he saw first responders lining 13th Street on Sunday afternoon. His first thought was that there was some kind of mass-casualty incident.

By the time Chartier got to the courthouse, a few people were still being treated by paramedics and he could see an oily residue on the ground, along with flags and shoes scattered nearby, he said.

“It was a very grim and unsettling scene,” Chartier said. “I grew up in Boulder and I’ve never experienced anything quite like that.”

Alexandra Posnack, 19, was at her Boulder home about five minutes away from Pearl Street when friends at the scene started texting her that someone had thrown a Molotov cocktail at the group holding the weekly demonstration calling for the release of Israeli hostages.

“I’m horrified and I’m also enraged, and I will be back here next week to protest with my big-ass Israeli flag,” she said.

Brandon Hoover, 28, said the attack doesn’t seem real.

He and his girlfriend were walking down Pearl Street when suddenly there were flames and “the smell of flesh,” he said.

“I thought, ‘Holy crap, that could have been any one of us on Pearl Street,’” Hoover said. “…Once you see something that traumatic, it’s going to stick with you.”

Hours later, the scene was still being swept by hazmat, canine and bomb disposal teams, Redfearn, the Boulder police chief, said. Parts of Pearl Street, including the 1200 through 1500 blocks, had been evacuated.

That section of the mall remained closed to the public as police cleared the area and investigated a “vehicle of interest,” Redfearn said.

Boulder resident Henry Bonn-Elchones, 18, was downtown getting lunch with friends when he saw smoke and burn marks and an Israeli flag on the ground by the courthouse.

He never heard an explosion. But he said first responders and law enforcement swarmed the area and later watched as two older women were loaded into ambulances.

‘Hate-filled acts’

Local political leaders condemned the attack on Sunday.

“Hate-filled acts of any kind are unacceptable,” Polis said in a statement on social media. “While details emerge, the state works with local and federal law enforcement to support this investigation.”

U.S. Rep. Joe Neguse, who represents Boulder in Congress, called for Americans to stop the spread of antisemitism.

“Tonight, as many prepare to mark the Shavuot holiday, our Jewish community has been subjected to yet another brutal and horrific act of violence,” said the congressman, whose district includes Boulder. “We stand with the Jewish community — today and always — and will be united in supporting the victims and their families, and to redoubling our efforts to stop antisemitism.”

Colorado Attorney General Phil Weiser wrote in a statement that the attack appears to be a hate crime and that he had offered his office’s support to Boulder District Attorney Michael Dougherty.

“People may have differing views about world events and the Israeli-Hamas conflict, but violence is never the answer to settling differences,” he wrote. “… We all have the right to peaceably assemble and the freedom to speak our views. But these violent acts — which are becoming more frequent, brazen, and closer to home — must stop and those who commit these horrific acts must be fully held to account.”