Investigators probing Gracie Mansion IED incident as act of ‘ISIS-inspired terrorism’

Investigators are treating a chaotic incident where two men allegedly attempted to detonate homemade bombs during a protest near Gracie Mansion over the weekend as an “act of ISIS-inspired terrorism,” Police Commissioner Jessica Tisch said Monday, referring to the Islamic State group.

The commissioner said the two suspects, 18-year-old Emir Balat and 19-year-old Ibrahim Kayumi, both from Pennsylvania, will be charged in federal court in Manhattan on Monday afternoon. She declined to comment on the charges until the criminal complaint is unsealed.

Tisch said initial forensic testing by authorities revealed one of the improvised explosive devices contained triacetone triperoxide, or TATP, “ a dangerous and highly volatile homemade explosive that has been used in IED attacks around the world.” She said the devices “could have caused serious injury or death,” and evidence samples were being sent to an FBI lab for additional testing.

Police arrested Balat and Kayumi as part of a federal-led investigation after someone threw a homemade explosive device during a Saturday protest near Gracie Mansion, the mayor’s official residence, on the Upper East Side. Law enforcement officials recovered a second explosive device nearby. Officials described both devices as jars containing nuts, screws and bolts.

Police said they were also testing a third “suspicious device” recovered from a vehicle on East End Avenue between East 81st and 82nd streets on Sunday. Officers secured the area for several hours and temporarily evacuated nearby buildings before reopening the block that night. Tisch said the car was a black 2010 Honda with New Jersey plates, and the device found inside tested negative for explosive materials.

Attorney information for Balat and Kayumi was not available Monday morning as they waited to appear before a judge.

Tisch spoke at a briefing with Mayor Zohran Mamdani outside Gracie Mansion on Monday morning. The mayor condemned the anti-Muslim protest organized by far-right activist Jake Lang where the attack occurred during a confrontation with counterprotesters.

Gov. Kathy Hochul said Monday that New York “remains in a heightened threat environment” following the incident and the ongoing war in Iran. She said state police are increasing their presence at “sensitive sites” across the state and supporting the NYPD’s probe as part of the FBI’s Joint Terrorism Task Force. More than 1,000 National Guard members are deployed on active duty “protecting critical transit sites across New York City,” the governor added.

Saturday’s protest created a tense confrontation, where Lang, who brought a goat and around 20 supporters dressed in “Freedom” sweatshirts, were met with about 125 counterprotesters.

Mamdani said the two arrested men had “attempted to bring violence to New York City.”

He also condemned the sentiment behind the Lang-led protest while defending the protesters’ rights.

“This was a vile protest rooted in white supremacy,” said Mamdani, the city’s first Muslim mayor. “While I found this protest appalling, I will not waver in my belief that it should be allowed to happen.”

He said that with the exception of the arrested men, many of the people in the crowd of counterprotesters were peaceful.

Both Mamdani and Tisch expressed gratitude to the NYPD. They were joined at the press conference by Assistant Chief Aaron Edwards and Sgt. Luis Navarro, who officials said both ran toward one of the ignited explosive devices.

The mayor and First Lady Rama Duwaji were not home during the attack, according to officials. Mamdani said the couple knew about the protest weeks in advance and were spending the day at the New York City Sign Museum in Brooklyn.

The FBI’s New York office declined to comment early Monday, referring to its previous statements about the incident. In a post on X on Sunday night, the bureau said it was working with the NYPD and other law enforcement agencies to investigate the two suspicious devices used near Gracie Mansion on Saturday and had confirmed they were “improvised explosive devices.”

The bureau added that its Joint Terrorism Task Force was planning to conduct interviews, review videos, collect evidence and pursue “all leads” in connection with the incident, and asked the public to submit tips at 1-800-CALL-FBI or on its website.

Balat is a student at Neshaminy High School in Middletown Township, Pennsylvania, according to the local school district’s community relations office. On Sunday evening, Superintendent Jason Bowman sent a letter to the school community, saying officials were “aware of the news reports” concerning an 18-year-old student.

“We understand that events receiving significant media attention can raise questions for families, staff and students,” Bowman wrote, adding that the district was communicating with law enforcement. “At this time, there is no information indicating any concerns related to our schools.”

Brothers Brandon and Gary Pozdnyakov, both recent Neshaminy graduates, said they knew Balat as a kid who mostly kept to himself at school. They also said they communicated with him from about 2022 to 2024 about buying and selling sneakers for a business the brothers ran at the time.

“We would buy a lot of shoes from him just because he would have those [computer] bots that would be able to get them right for retail,” Brandon Pozdnyakov told Gothamist. “He seemed very computer-smart.”

The brothers said Balat had worked with someone else to make the computer programs, which could purchase large quantities of sneakers in high demand. They would meet up with him to exchange the merchandise at a local Wawa, and Balat’s father was always with him, the Pozdnyakovs said.

“ It was literally always his dad dropping him off with shoes just to make sure everything was good,” Gary Pozdnyakov said, noting Balat’s father was more talkative than his son.

“Never seemed like he would do any harm, really, but always had that awkward kid in him,” Brandon Pozdnyakov said about Balat. The brothers said they lost touch with him in 2024, when they opened up a different business and he stopped texting them about shoes.

Kayumi is a 2024 graduate of Council Rock High School in Newtown, Pennsylvania, the local school district confirmed to Gothamist. The district told community members it is also in touch with law enforcement.

“At this time, there is no information indicating any threat or connection to Council Rock schools,” Superintendent Andrew Sanko wrote in a letter shared with Gothamist. “We encourage families to speak with their children if they have questions and to remind students to report any concerns to a trusted adult, counselor or school administrator.”

The U.S. attorney’s office for the Southern District of New York did not immediately respond to a request for comment.

The district’s top prosecutor, Jay Clayton, and Tisch were slated to hold a joint press briefing on Monday afternoon.

This is a developing story and has been updated with additional information.