New York City's police commissioner said Monday that authorities are investigating whether men who brought improvised explosive devices to a protest outside New York City's mayoral residence were inspired by ISIS.

The devices, which did not explode, were hurled during raucous counterprotests Saturday near Gracie Mansion during a "Stop the Islamic Takeover of New York City" event led by the far right activist Jake Lang. Police Commissioner Jessica Tisch said the explosives could have caused serious injury or death.

Two people are in custody for their alleged roles in the confrontation. Tisch said during a news conference that police are working with federal prosecutors and the FBI in investigating on the case. The FBI said agents with the bureau's Joint Terrorism Task Force were participating in the investigation.

"They are suspected of coming here to commit an act of terrorism," Mayor Zohran Mamdani said.

The two have not been charged. Tisch said police were working with federal prosecutors and the FBI on the case. The FBI said agents with the bureau's Joint Terrorism Task Force were participating in the investigation. She said investigators have found no apparent link to Iran or the war.

Authorities said they had "identified a suspicious device in a vehicle on East End Avenue between 81st Street and 82nd Street." Several streets were closed and "limited evacuations of buildings" were ordered as the bomb squad assessed and worked to remove the device, the post said.