The FBI has launched a terrorism investigation after improvised explosive devices were ignited outside New York City Mayor Zohran Mamdani's residence during a protest.

Two IEDs were thrown outside Gracie Mansion, Mamdani's residence, on Saturday by counter-protesters at an anti-Islam protest, CBS News reported. Two men from Pennsylvania were arrested at the protest over the IEDs, while four other people were also arrested on other charges.

Authorities said Monday a third device was discovered in a nearby vehicle but that it was not live.  

New York City Police Commissioner Jessica Tisch said Saturday that an anti-Islam protest was organized by people associated with Jake Lang, a pardoned Jan. 6 rioter and far-right influencer. Unnamed law enforcement sources told the news outlet that a group of more than 100 counter-protesters also gathered, and two young men from Pennsylvania, angered by the anti-Islam protest of about 20 people, brought the IEDs to the gathering, intending to cause harm.

The IEDs consisted of a sports drink bottle with explosive material inside, set in glass jars and surrounded by nuts and bolts, wiht a fuse that was apparently connected to an M80-type firework, according to law enforcement sources. Two sources said that the IEDs contained volatile explosive material triacetone triperoxide, or TATP.

The New York Police Department said that another suspicious device was found Sunday in a vehicle about three blocks south of the park where Gracie Mansion is located, prompting "limited evacuations of buildings in the vicinity while the Bomb Squad assesses and removes the device."

The NYPD said later Sunday that the device was safely removed for further testing.

The FBI's Joint Terrorism Task Force launched a terrorism investigation, and search warrants were expected to be executed in Pennsylvania and New Jersey, according to sources.

Videos of the protests show a man apparently yelling "Allahu Akbar" as a protester, identified as 18-year-old Emir Balat, of Pennsylvania, allegedly throws an "ignited device." At least one source has told authorities that attack was "ISIS inspired."

According to sources, investigators are looking to determine if at least one of the subjects was inspired by ISIS extremist messaging.

Tisch said that the first device thrown by Balat extinguished itself after striking a barrier in a crosswalk near police officers. He then ran away and allegedly retrieved a second device from 19-year-old Ibrahim Kayumi of Pennsylvania, lit the device, and started running with it before dropping it, she said.

Both Balat and Kayumi were taken into custody. Police also arrested 21-year-old Ian McGuiness, who allegedly used pepper spray on counter-protesters, and three others on disorderly conduct and obstruction charges.

Investigators are looking into Balat and Kayumi's overseas travel. Balat, whose parents were naturalized as U.S. citizens in 2017 after emigrating from Turkey, left the U.S. for several months and traveled to Istanbul from May 6 to Aug. 26, 2025, and then this January. 

Balat is a U.S. citizen and has been living with his family in Pennsylvania. The residence is reportedly in Bucks County and was also visited by authorities.   

Kayumi, whose parents are originally from Afghanistan and became naturalized U.S. citizens in 2004 and 2009, traveled to Istanbul for several weeks in July and August 2024 and to Saudi Arabia in March of that year. 

Mamdani and his wife were inside their residence at the time of the protest.

The mayor posted on X on Sunday, "Yesterday, white supremacist Jake Lang organized a protest outside Gracie Mansion rooted in bigotry and racism. Such hate has no place in New York City. It is an affront to our city’s values and the unity that defines who we are.

"What followed was even more disturbing. Violence at a protest is never acceptable. The attempt to use an explosive device and hurt others is not only criminal, it is reprehensible and the antithesis of who we are. I want to thank the brave men and women of the NYPD who acted quickly to keep New Yorkers safe. Our officers ran toward danger without hesitation, demonstrating once again the courage and dedication it takes to protect this city every single day."