Two men accused of trying to bomb a protest outside the New York City mayor’s home wanted to kill up to 60 people in the name of the Islamic State group (IS), federal prosecutors allege.

An Indictment, released on Tuesday, details charges against 18-year-old Emir Balat and 19-year-old Ibrahim Kayumi

“All I know is I want to start terror, bro,” one of the men allegedly said in a recorded dashcam video. “I want to petrify these people.”

The pair are charged with attempting to detonate two explosives outside Gracie Mansion, the official residence of mayor Zohran Mamdani. The 7 March incident happened during an anti-Islam protest, and none of the explosives went off as intended.

Police have alleged the men wanted the March attack to be “even larger” than the 2013 Boston Marathon bombing that left three dead.

Authorities say they found a notebook and three days’ worth of dashcam video and audio in the vehicle that the pair, both US citizens from Pennsylvania, used. Authorities say they found a third bomb in the car.

The notebook included a list of the materials needed to assemble and subsequently detonate a homemade bomb, according to the indictment.

The notebook also included details of alternative plans for an attack, including using a vehicle to target a festival, parade, protest or celebration, according to the court document.

The dashcam captured hours of Balat and Kayumi driving and discussing their alleged plans.

The indictment alleges that dashcam video includes a conversation where Balat said they were “gonna kill about 8 to 16 people,” or as many as 30 to 60 people if the area where the bombs detonated were crowded.

Balat and Kayumi both waived their constitutional rights to remain silent after their arrest, according to court documents.

After his arrest Balat requested a piece of paper and wrote on it that he pledges allegiance to IS and called for death of nonbelievers or infidels, according to the criminal complaint obtained by the BBC.

Kayumi stated that he was affiliated with IS, watched IS propaganda on his phone and was partly inspired to carry out his actions that day by IS, court records said.

Footage of the incident shows one of the suspects being detained just seconds after an explosive is ignited, which did not detonate. No one was injured.

Mamdani and his wife Rama Duwaji were not home at the time.

Balat and Kayumi have been in custody since their arrest on 7 March. (BBC)

•Ibrahim Kayumi, left, and Emir Balat were arrested outside Gracie Mansion last month.Madison Swart/Reuters

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