The New York City Police Department told BBC News that the police "investigation is ongoing" into the fire incident outside the Manhattan courthouse where Donald Trump is standing trial.

A police spokeswoman said that the NYPD responded to the incident after receiving a 911 call around 13:37 local time (18:37 BMT).

She said the man who lit himself on fire was taken to hospital in "critical condition", and she added that there were "no additional safety concerns at this time".

Police will hold a press conference shortly.

You will be able to watch live by pressing the play button at the top of this page.

Our reporter in New York, Nada Tawfik, describes the moment when a young man set himself on fire in front of the court house where Donald Trump's historic trial was underway.

Kayla Epstein
Reporting from outside the courthouse

One witness says he was checking out the scene around the courthouse when he saw the person set themselves on fire.

Dave, an older man from the Upper West Side, looked visibly shaken as he spoke to the press. He asked we not use his last name or publish his image.

The incident was something “I never wanted to see", he says.

“It’s going to be in my nightmare," he says. “It happened pretty fast.”

When asked if anyone tried to help, he says: “What do you do?”

Dave says people were horrified and started screaming when they realised what was happening.

“He was up in flames and seemed obviously determined,” he says.

The New York Fire Department reported that "an individual on fire" is in critical condition.

He was transported to New York–Presbyterian Hospital, the fire department said.

We've just heard from Julie Berman, a witness and Manhattan resident who saw what happened at court.

She says the man who set himself on fire has been at court all week carrying a sign.

She says he threw papers in the air after dousing himself in some sort of liquid.

He doused himself twice, she says.

"The whole thing, it happened so fast, and it took my mind so long to catch up — kind of like the earthquake, it took me like 20 seconds to figure out what was going on," she says.

She says the man may have asked her to stop intervening or get away from him before he lit himself on fire.

Berman says he reminded her of activists "in my youth in the 90s, when I was in my 20s".

As news of the man lighting himself on fire broke, Trump was in the courtroom.

Shortly after, he spoke to a Secret Service agent, and then left the courthouse, video shows.

We are unsure of his whereabouts now, and the former president ignored questions from the press.

The New York Police Department has told reporters on the scene that there are no safety concerns at the moment.

Image source, Reuters

The New York Police Department says the man has been transported to a nearby hospital in a critical condition.

They received a call about 13.37 (local time) that a male appeared to have set himself on fire in the vicinity of Centre Street.

Kayla Epstein
Reporting from outside the courthouse

Reporters leaving the courthouse were greeted by the flashing lights of ambulances and the wail of sirens.

You can still see smoke smouldering from the spot where the person set themselves on fire, and the air has an acrid smell.

The breeze is blowing the smoke toward the courthouse.

There is burned debris and what appears to be a few scattered pieces of paper or fliers nearby.

The park is closed and a few dozen police are already at the scene. I counted at least four ambulances around the park.

Nada Tawfik
Reporting from outside the courthouse

Just moments ago, a young man doused himself in a liquid and lit himself on fire in the park in front of the courthouse, after throwing coloured pamphlets in the air.

Press here covering the trial saw it happening and everyone in the area started screaming.

There’s a massive police presence and officers ran into the park and shouted for a fire extinguisher.

He was carried away on a stretcher, his body very badly burned.

The New York Police Department is still on the scene and his motive is unclear.

Kayla Epstein
Reporting from court

The judge made no mention of what what had just happened outside the courthouse, but awareness is quickly spreading here in the overflow room.

We can hear sirens up here on the 15th floor. We are now being allowed to leave.

Someone outside the court has appeared to set themselves on fire.

It's a rapidly unfolding situation, we will bring you more updates shortly.

Kayla Epstein
Reporting from court

The final two alternates are chosen. "We have our full panel," Justice Merchan says once all six alternate seats are filled. He calls them back.

Kayla Epstein
Reporting from court

Trump's defence team is raising challenges to potential alternate jurors.

One person made social media posts from anti-Trump protests around the time he was elected and sworn in as president.

Justice Merchan is describing the posts, presented to him by Trump's lawyers.

One post said "Enormous crowd. Great signs. I love New York".

Another post showed signs that used profanity.

The man says said he found the signs “really interesting” and claimed he viewed one of the protests as a women's rights march.

But Justice Merchan wasn’t convinced, and granted Trump’s lawyer’s request to strike him. The man is dismissed.

Kayla Epstein
Reporting from court

So far today, Justice Merchan has seated three new alternate jurors.

That brings the total seated alternates to four.

We have two more to go.

They still need to be sworn in.

Kayla Epstein
Reporting from court

Justice Merchan is now starting the process of seating alternate jurors, and hearing challenges from both sides.

Kayla Epstein
Reporting from court

Image source, Reuters

When jurors answer questions about themselves and their personal lives, Donald Trump either follows along with the questionnaire or leans back in his seat, looking, frankly, a bit bored.

But as the potential alternate jurors start to discuss how they feel about Trump, his posture changes.

He physically turns in his seat to face them, and leans forward as he listens.

New Yorkers share range of opinions about him.

One woman says “I’m not even sure what Trump’s policies are,” but that she does not like the “negative” actions she believes he inspires in his base.

Another says he just sees Trump as a person, much like himself.

A man who immigrated to the US from a Scandinavian country says he likes low taxes and policies that support the tech industry, which he believes Trump supports.

But he does not like Trump’s affiliation with the Republican party, which he says limits women’s rights and is too focused on religion.

Another man says that growing up in the region, Trump Tower was a "positive" symbol for him, but now felt his "rhetoric" was harmful. He said his opinion was "negative".

Kayla Epstein
Reporting from court

Image source, Getty Images

Donald Trump is at his most attentive right now. He turns his body in his seat as he watches his lawyer, Susan Necheles, question the jurors.

And he listens as yet another potential alternate juror says that, after hearing the questions, she is feeling anxiety and self-doubt.

She asks to speak to the judge, and after they talk, he excuses her.

This is the third person today to get dismissed because they told Justice Merchan they felt anxiety about the case.

Kayla Epstein
Reporting from court

Susan Necheles, one of Trump’s lawyers, is now going to question the potential jurors.

“What we’re trying to understand here is people’s biases,” she tells them.

“We all bring biases… we particularly bring bias about someone who is as public and outspoken” as Trump, she says.

She asks them to do the best that they can to be honest.