A man has set himself on fire during the criminal trial of former United States President Donald Trump at a park opposite the courthouse in New York.

The man poured a liquid over himself and set himself alight on Friday, reports from various media outlets, including the New York Times and CNN revealed.

Bystanders had screamed and tried to help, the reports said.

After a short time, police officers arrived and extinguished the flames.

The man was then carried into an ambulance and driven away.

It was unclear why he set himself on fire.

On Saturday, the New York City police department said the man, identified as Max Azzarello of St Augustine, Florida, was declared dead at a local hospital where he was taken for treatment after the incident on Friday.

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Police said the man, who was born in 1987, did not appear to be targeting Trump or others involved in the trial.

During the incident, the fourth day of Trump’s trial on criminal charges of falsifying business records, Azzarello threw pamphlets in the air before using an alcohol-based cleaning substance to douse himself and light the fire.

Police had said earlier that he was being viewed “as sort of a conspiracy theorist”.

The incident took place in Collect Pond Park, directly opposite the courthouse where the criminal trial of Trump is currently taking place.

The courthouse is extensively cordoned off and numerous police officers are on permanent duty there.

Dozens of media representatives with cameras and broadcast vans are gathered around it.

Opponents and supporters of Trump are allowed to gather for demonstrations in the park, but so far only a few have done so on the days of the trial.

The grounds are surrounded by barricades, but there are also open entrances.

Trump, the first former U.S. President to face criminal charges, is on trial in connection with hush-money payments he allegedly made to adult film star Stormy Daniels.

The Star