A man has thrown conspiracy theory pamphlets in the air before setting himself on fire outside the New York courthouse where former US President Donald Trump is on trial.

Police have identified the man as Maxwell Azzarello, in his mid-30s, from St Augustine in Florida. He is now in critical condition in hospital after setting himself alight in a designated protest area for pro and anti-Trump demonstrators.

The NYPD said it has opened an investigation after its officers responded to the fire at around 1:37pm local time on Friday (6:37pm UK time). Mr Azzarello took a canister out of his bag containing what is believed to have been an alcohol-based accelerant, before dousing himself in the fluid and setting himself ablaze, police said.

Officers and civilians ran into the protest area and attempted to put out the flames using coats and fire extinguishers, NYPD Chief of Department Jeff Maddrey told reporters. Four police officers suffered minor injuries from fire exposure, authorities said.

NYPD Chief of Detectives Joseph Kenny told reporters: "The pamphlets appear to be propaganda-based, almost a conspiracy theory type of pamphlet. Some information in regards to a Ponzi scheme and the fact that some of our local educational institutes are fronts for the mob.

So, a little bit of a conspiracy theory going on here." The blaze broke out after jury selection for Trump's hush money trial concluded with 12 people, and six alternatives, chosen to decide whether the former US president covered up payments to women who alleged they had affairs with him. The Trump campaign released a statement on Friday afternoon offering its "condolences to the traumatised witnesses" after the blaze.

Read more:Who is the porn star at the centre of Trump's hush money case?Trump blasts trial as a 'disgrace' Karoline Leavitt, the national secretary for his campaign, said: "Not knowing the motivations behind this sickening situation, it's difficult to make any definitive remarks, other than to say we are thankful that to the best of our present knowledge, nobody other than the individual in question was hurt." She added: "Today is more proof that our nation is in deep trouble... Make America Great Again." Footage shared on social media shows Mr Azzarello lying on his back on the pavement outside the courthouse while the lower part of his body is on fire.

Another man sprays him with a fire extinguisher which appears to put the fire out. Police officers are seen running over to the scene as the fire is extinguished.

Freelance photojournalist Ed Quinn was outside the court at the time and told Sky News' US partner network NBC News: "I heard someone scream 'He's going to light himself on fire!'.' "I see him dumping gasoline on his face, very deliberately. "He had a grey T-shirt on.

It soaked his face. It soaked his shirt.

Boom, he went up." Mr Quinn said it took the police about a minute to arrive. He continued: "Women were begging, screaming, put it out, put him out." Trump facing multiple charges in historic trial Hours after the jury members were decided on Friday, an appeals court judge rejected a last-minute bid by Trump to halt the trial over his claims that the jury selection process was unfairly rushed.

The judge also said he would not consider Trump's immunity motion that was filed just before the hush money trial began. Opening statements in the trial are scheduled to take place on Monday.

In what is the first criminal trial of a former US president, Trump is accused of criminally altering business records to cover up a $130,000 (£104,200) payment to adult film actress Stormy Daniels, real name Stephanie Clifford, during his 2016 election campaign. Ms Daniels and former Playboy model Karen McDougal, who was paid $150,000 (£120,000), both claim to have had affairs with Trump.

His lawyers say the payment was meant to spare himself and his family embarrassment, not help him win the election. Click to subscribe to the Sky News Daily wherever you get your podcasts Trump is facing 34 felony counts of falsifying business records and could get up to four years in prison if convicted.

He is also facing three other criminal cases that could go to trial. Trump has pleaded not guilty to all charges.

In court, one prospective juror was excused after saying she suffers from anxiety and felt she could struggle to be impartial, while another was called to the judge's bench after bursting into tears. The first woman said she takes medication and that as the days go on "I don't think I will be able to be completely fair".

The second broke down crying and, according to Sky News' partner NBC News, said: "I have to be honest, I feel so nervous and anxious right now. I'm sorry.

"I thought I could do this... I don't want you to feel like I've wasted anyone's time," she added before being called to the bench and excused.".