An investigation into New York City’s alleged “ISIS-inspired” terrorist attack reportedly resulted in a controlled detonation of additional explosive devices discovered in a storage facility, authorities said.

Neither of the improvised explosive devices (IEDs) thrown at a rally in the city detonated during the incident. Officials said additional devices were found in a storage unit in the suspects’ hometown Monday night, a federal source told Fox News. (RELATED: Zohran Mamdani Cries Islamophobia After Alleged ‘ISIS-Inspired’ Attack — Then Tries Cleaning Up Next Day)

The rally was organized by right-wing demonstrators, and authorities said Islamic counter-protesters were responsible for the attack, according to officials.

The investigation led the Federal Bureau of Investigation (FBI) to Bucks County, Pennsylvania, where suspects 18-year-old Emir Balat and 19-year-old Ibrahim Kayumi reportedly reside.

Balat had been enrolled in online courses with the local high school at the time of the incident, according to CBS News, citing a school spokesperson.

Balat and Kayumi were charged in the Southern District of New York with attempting to support ISIS, using a weapon of mass destruction and transporting explosive material, the charging documents show.

Investigators said the devices, if detonated in the city, could have caused catastrophic harm, Fox News reported.

The outlet shared a video from outside the storage unit in which a loud explosion is audible during the controlled detonation.

New York Police Commissioner Jessica Tisch said the explosives were a legitimate threat, and that the devices contained triacetone triperoxide (TATP) — a volatile homemade explosive commonly referred to as the “mother of Satan.”

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

Deputy Attorney General Todd Blanche said in a press release that Balat and Kayumi allegedly aimed to create an explosion deadlier than the 2013 Boston Marathon bombing, which resulted in three fatalities.

“These men allegedly sought to inflict mass casualties in service to ISIS with the hope of exceeding the carnage of the Boston Marathon bombing,” the press release said Monday.

Both suspects are U.S. citizens. Their parents are naturalized U.S. citizens, with one set from Turkey and the other from Afghanistan, according to Fox News.

The Daily Caller reached out to the FBI but has not heard back as of publication.