A former US Army soldier has been arrested after setting a fire outside a federal building in New York City, the FBI says.

Andrew Arrabaca, 43, allegedly fired a pellet gun and set off fireworks Monday morning at 26 Federal Plaza, where the FBI, Immigration and Customs Enforcement (ICE) and U.S. Citizenship and Immigration Services have offices.

Federal agents approached the suspect, who they say was armed with a machete and other weapons.

Three people suffered minor injuries in the incident, including an immigrant who was attending a status hearing, the FBI said. The site in lower Manhattan has become a flashpoint for protests against President Donald Trump’s immigration policies.

The suspect, whom the Department of Homeland Security (DHS) called an “anti-ICE rioter,” set off fireworks before pouring an accelerant on the stairs of an entrance to the building, causing a fire. The BBC has contacted DHS for comment.

Firefighters put out the fire.

Arrabaca “made several anti-government and anti-ICE statements during the incident,” the FBI said.

FBI New York Deputy Director James Barnacle said during a news conference that Arrabaca was armed with two axes, a machete, three knives and fireworks.

He fired between five and seven pellets from an airsoft gun in the direction of the building, Barnacle said.

Of those injured, two were government employees, Barnacle said.

DHS said a bystander was grazed and a security officer who stopped and detained Arrabaca suffered minor injuries.

“He is an anti-American, anti-government extremist,” Barnacle added.

Arrabaca, from Poughkeepsie, New York state, served in the regular army from 2001 to 2004 and in the New York Army National Guard from 2004 to 2005, according to BBC US partner CBS.

He had no deployments and left the Army with the rank of specialist.

New York City Mayor Zohran Mamdani called the incident “deeply disturbing” in a post on X.

“Our administration will continue to ensure that all New Yorkers are safe in their city and will hold accountable anyone who threatens that,” he said.