Investigators are looking to determine if at least one of the two men arrested after an explosive device was ignited outside New York City Mayor Zohran Mamdani’s residence over the weekend was inspired by ISIS extremist messaging online, law enforcement sources told CBS News. Two men from Pennsylvania were arrested outside Gracie Mansion, the home of Mamdani and his wife.
“I can confirm this morning that this is being investigated as an act of ISIS-inspired terrorism,” New York City Police Commissioner Jessica Tisch said during a news conference Monday.
Mamdani told reporters that the two men — 18-year-old Emir Balat and 19-year-old Ibrahim Kayumi — were seen on video throwing two devices toward protests outside Gracie Mansion on Saturday. The FBI said the devices contained explosive materials and fragmentation that could have killed and maimed numerous people.
A federal terrorism investigation is underway, and federal prosecutors in New York unveiled charges Monday against Balat and Kayumi. They are each being charged with five counts, including attempted support to a designated foreign terrorist organization; use of a weapon of mass destruction; and transportation of explosive materials, according to the federal criminal complaint.
ISIS, al Qaeda and pro-Iranian groups have intensified recruiting and calls for violence online since the war with Iran started just over a week ago, the law enforcement sources told CBS News. The group had stepped up efforts over the last 18 months, which have intensified since the conflict started. An intelligence source noted this took place during the Muslim holy month of Ramadan, and at a time when the intelligence community has seen that impressionable young men who are prone to violence feel justified to act.
Tisch told reporters on Saturday that an anti-Islam protest was organized by people associated with Jake Lang, a pardoned Jan. 6 rioter and far-right influencer. A group of counter-protesters, numbering more than 100, also gathered, and two young men from Pennsylvania, angered by the anti-Islam protest, brought the homemade bombs to the gathering, intending to cause harm, law enforcement sources told CBS News.
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The NYPD’s Bomb Squad sent the devices to the FBI’s Quantico lab for analysis. One of the devices was determined not to be a “hoax device or a smoke bomb,” but instead it was “an improvised explosive device (IED) that could have caused serious injury or death,” Tisch said in a statement Sunday. The FBI and NYPD later confirmed both items to be IEDs, the bureau’s New York office said on X.
Law enforcement sources told CBS News that the devices consisted of a sports drink bottle filled or partially filled with explosive material set inside glass jars and surrounded by fragmentation, or nuts and bolts. The fuse was apparently connected to an M80-type firework.
Two sources told CBS News that the IEDs contained triacetone triperoxide, or TATP, a volatile explosive material. It is often synthesized from acetone and hydrogen peroxide, appearing as a white crystalline powder.
Another suspicious device was found Sunday in a vehicle on East End Avenue about three blocks south of the park where Gracie Mansion is located, the NYPD said, prompting “limited evacuations of buildings in the vicinity while the Bomb Squad assesses and removes the device.”
The device was safely removed for further testing, the NYPD said later Sunday, providing CBS News with an image of a black vehicle that was searched by the bomb squad.
The FBI’s Joint Terrorism Task Force has taken the lead and launched a terrorism investigation. Search warrants were expected to be executed in Pennsylvania and New Jersey, sources told CBS News.
Videos showing the chaos from the protests, verified by the CBS News Confirmed team, show a man apparently yelling “Allahu Akbar” – or “God is Most Great” – just as a protester, identified as Emir Balat allegedly throws an “ignited device.”
Investigators are looking to determine if at least one of the subjects was inspired by ISIS extremist messaging, sources told CBS News.
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Tisch described the device as “a jar wrapped in tape, importantly with nuts, bolts and screws along with a hobby fuse.”
According to Tisch, the first device thrown by Balat extinguished itself after striking a barrier in a crosswalk, a few feet from police officers.
Balat then ran away and allegedly retrieved a second device from Ibrahim Kayumi, lit the device and started running with it before dropping the device, Tisch said.
Balat and Kayumi were taken into custody. Police arrested a person, identified as 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 the overseas travel for Balat and Kayumi. Balat left the U.S. for several months and traveled to Istanbul from May 6 to Aug. 26, 2025. He most recently traveled back to the U.S. from Turkey in January of this year. Meanwhile, Kayumi traveled to Istanbul for several weeks in July and August 2024 and to Saudi Arabia in late March of that year.
Federal investigators have also been interviewing family members of Balat and Kayumi as part of their investigation, as well as looking at their online communications.
Balat’s parents were born in Turkey and were naturalized as U.S. citizens in 2017. Balat is a U.S. citizen and has been living with his family in a large two-story home in Pennsylvania. A woman at the residence confirmed to CBS Philadelphia that Balat lived at the house.
Kayumi’s parents are originally from Afghanistan. They became naturalized U.S. citizens in 2004 and 2009. It is unclear if Kayumi was living with them at the time of the incident Saturday.
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In a statement on Sunday, Mamdani specifically mentioned Lang and said the protest outside Gracie Mansion was “rooted in bigotry and racism” and has no place in New York City.
“It is an affront to our city’s values and the unity that defines who we are,” he said.
He did not name the two men who were arrested for the IEDs. Instead, he said, “The attempt to use an explosive device and hurt others is not only criminal, it is reprehensible and the antithesis of who we are.”