Throwing of explosive devices outside Mamdani residence was ‘act of Isis-inspired terrorism’, officials say

The throwing of two improvised explosive devices – allegedly by counter-protesters during an anti-Islam demonstration – outside the residence of New York mayor Zohran Mamdani on Saturday was an act of “terrorism” inspired by the Islamic State terror group, officials said Monday.

Jessica Tisch, the New York police department (NYPD) commissioner, told reporters at a press conference in Manhattan that two men from Pennsylvania were arrested at the scene – and that a federal criminal complaint against them would be filed later on Monday.

The incident took place on Saturday during an anti-Islam protest by rightwing agitators outside Gracie Mansion on Manhattan’s upper east side, when Mamdani, the city’s first Muslim mayor, and his family were not at home.

The devices, which Tisch said contained triacetone triperoxide (TATP), a homemade and highly volatile chemical explosive known as “mother of Satan”, were allegedly thrown by counterprotesters she named as Ibrahim Kayumi, 19, and Emir Balat, 18.

Neither device exploded, and both were made safe by the NYPD bomb squad.

“These were not hoax devices, nor smoke bombs,” Tisch said. “They were improvised explosive devices that could have caused serious injury or death.”

Tisch said she would “be able to say much more about the investigation and what we have learned in this case” after the complaint against Kayumi and Balat is made public. Nonetheless, Tisch said she could “confirm that this is being investigated as an act of Isis-inspired terrorism.”

Mamdani said the men had “traveled from Pennsylvania and attempted to bring violence to New York City”. The mayor praised two NYPD officers whose “swift and decisive actions” he said led to the suspects’ prompt arrest as well as the devices being removed safely.

“New York City will never tolerate violence, whether from protests or counter-protests,” he said, referring to the Stop the Islamic Takeover of New York City demonstration of about 20 people organized by far-right influencer Jake Lang, and dozens more who turned up to oppose it.

“Many of the counter-protesters met this display of bigotry peacefully with a vision of a city that is welcoming to all, but a few did not.

“Anti-Muslim bigotry is nothing new to me, nor is it anything new for the one million or so Muslim New Yorkers who know this city as our home. While I found this protest appalling, I will not waver in my belief that it should be allowed to happen.”

Six people were arrested at the protest, which the New York Times reported featured several violent skirmishes, the throwing of raw eggs, and at least one of Lang’s supporters pepper-spraying a counter-protester.

Tisch said the NYPD was already on a heightened state of alert for terrorist acts because of the US and Israeli military strikes in Iran that began on 28 February. But Tisch said “we do not have any information that connects this investigation to what’s going on overseas in Iran”.

Tisch added that the investigation was in its preliminary stages. And she said there was nothing so far that suggested the two arrested men had made any threats on social media or announced their intention to travel from Pennsylvania to New York.

She said a third suspected device “consistent with the first two explosive devices” was found in a 2010 Honda tied to the suspects and parked nearby. The device was removed by a robot and tested negative for explosives. She said there was no information about a possible third suspect linked to the arrested men.

Only one of the thrown devices was confirmed to contain TATP, Tisch said, and both were sent to an FBI explosives lab for further testing. The commissioner said the last time an improvised explosive device was used in New York City was a 2017 terrorist attack on the Manhattan subway that injured four people.

“We were fortunate that the devices used this weekend did not cause the kind of harm that they were certainly capable of causing,” she said.

“But luck is never a strategy. Devices like these have the potential to cause devastating harm, which is why the NYPD does thorough counter-terrorism investigations and treats every incident of this kind with the highest level of urgency and care, and it is why we remain vigilant.”