Two teenagers, who were allegedly inspired by the Islamic State (IS) extremist group, have been charged with terrorism offences following an incident at an anti-Muslim protest in New York.

Emir Balat and Ibrahim Kayumi appeared in court on Monday after a homemade bomb was allegedly thrown during a demonstration led by the far-right activist Jake Lang on Saturday, which also attracted a larger group of counter-protesters.

Rival groups clashed at the “Stop the Islamic Takeover of New York City” rally near Gracie Mansion, the home of Zohran Mamdani, a Democrat and New York’s first Muslim mayor.

Balat, 18, and Kayumi, 19, ‌are accused of travelling from Pennsylvania with improvised explosive devices (IEDs).

“Balat and Kayumi sought to incite fear and mass suffering through this alleged attempted terror attack in the backyard of an elected city official,” James Barnacle, who runs the FBI’s New York office, told reporters after their court appearance.

According to the criminal complaint, Balat was captured in footage lighting a small IED and throwing it towards the anti-Muslim protesters before lighting a ​second device handed to him by Kayumi and dropping it.

Police ‌were able to intercept the smoking devices, which were constructed with jars containing screws and bolts and the explosive substance TATP. The IEDs did not explode.

Court documents alleged that after the pair were arrested, ​they said they were inspired by IS, also called ISIS.

Balat allegedly told police that he wanted to carry out an attack “even bigger” than the Boston Marathon bombing in 2013.

Court filings said that during his interview, Balat admitted pledging allegiance to IS, while Kayumi said he watched IS videos on his phone.

Balat and Kayumi are each charged with using a weapon of ​mass destruction, attempting to provide material support to a designated foreign terrorist organisation, and three explosives charges.

The men are reported to have travelled to New York in a vehicle registered to one of Balat’s relatives, which was discovered near where they were arrested.

A search of the car revealed a fuse, a metal can, and a list of chemical ingredients and components that could be used to build explosives, the criminal complaint said.

Read more from Sky News:
Call for King’s US state visit to be cancelled
Attempted murder arrest after shots fired at Rihanna’s home

Rebecca Weiner, deputy police commissioner, told reporters on Monday that controlled detonations of the IEDs from the protest “revealed a significant explosion”, adding that they could have caused “death” and “destruction”.

In remarks on Monday, Mr Mamdani characterised the anti-Muslim demonstration as a “vile protest rooted in white supremacy” – but defended residents’ rights to hold peaceful demonstrations.

“While I find this protest appalling, I will not waver in my belief that it should be allowed to happen,” he said.

Meanwhile, US attorney general Pam Bondi said on social media that authorities “will not allow ISIS’s poisonous, anti-American ideology to threaten this nation”.

The anti-Muslim rally’s organiser, Mr Lang, was previously charged with assaulting an officer with a baseball bat, civil disorder and other crimes before being pardoned as part of Donald Trump’s sweeping act of clemency for defendants connected to the January 6 riots in Washington DC.