A suspect in the New York City terror protest attack near Gracie Mansion, the residence of Mayor Zohran Mamdani, allegedly planned an assault “bigger than the Boston Marathon bombing,” federal prosecutors said in a criminal complaint Monday.

Emir Balat allegedly made the statement after his arrest. Prosecutors say he told investigators that he and co-defendant Ibrahim Kayumi wanted to stage an attack exceeding the 2013 bombing that killed three people and injured more than 500 others.

The complaint alleges that on Saturday, Balat and Kayumi attempted to detonate two apparent explosive devices during a “Stop the Islamic Takeover of New York City” protest and counter-protest near Mamdani’s residence. 

Preliminary testing indicates that at least one device contained triacetone triperoxide (TATP), a highly volatile explosive used in multiple terrorist attacks over the past decade.

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Both men allegedly made statements referencing ISIS, with Kayumi captured on NYPD bodycam footage responding “ISIS” when asked why he carried out the attack, according to the complaint.

Prosecutors said Balat also later wrote on a piece of paper that he “pledge[d] allegiance [sic] to the Islamic State.”

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The two defendants face five federal charges: attempted provision of material support and resources to a designated foreign terrorist organization; use of a weapon of mass destruction; transportation of explosive materials; interstate transportation and receipt of explosives; and unlawful possession of destructive devices.

Balat and Kayumi appeared in handcuffs and shackles at the United States District Court for the Southern District of New York in downtown Manhattan on Monday.

A preliminary hearing is scheduled for April 8.

Following a NYPD and Justice Department news conference announcing the indictments against Balat and Kayumi, Mamdani confirmed the charges against the men in a statement. 

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“Emir Balat and Ibrahim Kayumi have been charged with committing a heinous act of terrorism and proclaiming their allegiance to ISIS,” Mamdani said. “They should be held fully accountable for their actions.

“We will continue to keep New Yorkers safe. We will not tolerate terrorism or violence in our city.”