A man has set himself on fire outside the New York courthouse where former U.S. President, Donald Trump is facing trial in the hush-money case.

Reuters reports that the man did not appear to have been targeting Trump.

It was reported that the man burnt for several minutes in full view of television cameras that were set up outside the courthouse, where the first-ever criminal trial of a former U.S. president was being held.

“He was on fire for quite a while,” one witness, who declined to give his name, told reporters. “It was pretty horrifying.”

Officials said the man, who is in his late 30s, survived and was in critical condition at a hospital.

The man was said to have pulled pamphlets out of a backpack and threw them in the air before he doused himself with a liquid and set himself on fire.

One of those pamphlets included references to “evil billionaires” but portions that were visible to a Reuters witness did not mention Trump.

In a news conference, investigators said they had received a 911 emergency call at around 13:30 local time (18:30 BMT) telling them that a man had lit himself on fire.

They identified him as Maxwell Azzarello, who had arrived in New York from his home in Florida sometime in the past week.

He has no criminal record in New York, and his family in Florida were unaware that he had travelled to the city.

New York Police Chief Jeffrey Maddrey said Azzarello was seen “shuffling around” in the park before reaching into a bag for the flammable liquid and pamphlets.

The pamphlets were “propaganda-based”, said Chief Maddrey, adding that they were regarding a “conspiracy theory”. The fuel appears to be an alcohol-based cleaning product.

There was a massive police presence outside the courthouse because of the trial, and officers quickly ran into the park shouting for a fire extinguisher.

Azzarello was carried away on a stretcher, his body very badly burned. The police said he was taken to a hospital burn centre in critical condition.