A home-made bomb was thrown outside the official residence of New York City Mayor Zohran Mamdani during a protest on Saturday, police said.
Officials said on Monday that the incident was being investigated as an "act of ISIS-inspired terrorism".
Emir Balat and Ibrahim Kayumi, both of Pennsylvania, were taken into custody after the incident and face charges including attempted support to a designated foreign terrorist organisation, use of a weapon of mass destruction and transport of explosive materials, the federal criminal complaint states.
Mr Balat and Mr Kayumi appeared in court on Monday, with a hearing set for April 9.
The incident unfolded during a demonstration organised by far-right influencer Jake Lang outside the Mayor’s house in Manhattan. Police said the device did not explode and no injuries were reported.
They said that the devices were jars wrapped in tape and containing nuts, bolts and screws.
The anti-Muslim protest, titled “Stop the Islamic Takeover of New York City, Stop New York City Public Muslim Prayer", took place halfway through Ramadan and drew about 20 demonstrators, while about 125 counter-protesters gathered near by, police said.
Mr Lang appeared with a goat and a small group of supporters wearing American flag hats and sweatshirts bearing the word “Freedom", echoing slogans associated with assassinated conservative activist Charlie Kirk.
In a statement on Sunday, Mr Mamdani condemned the protest and the violence that followed.
“Yesterday, white supremacist Jake Lang organised a protest outside Gracie Mansion, rooted in bigotry and racism,” Mr Mamdani said.
“Violence at a protest is never acceptable. The attempt to use an explosive device and hurt others is not only criminal, it is reprehensible and the antithesis of who we are.”
On Monday, Mr Mamdani said police had determined the explosive devices were made "to injure, maim or worse".
“Anyone who comes to New York City to bring violence to our streets will be held accountable in accordance with the law,” he said.
