Secretary of Transportation Pete Buttigieg has issued a statement saying he is monitoring the situation closely. He has pledged that his department - which works to ensure the safe passage of people across the country - will work with the New York metro transit authority to help in any way possible.

Harry Low
Reporting from Brooklyn

There are flashing lights are far as the eye can see along 4th Street in Brooklyn.

A mobile respiratory unit has arrived along with the NYC bomb squad.

The heavy police presence is almost matched by reporters here in Brooklyn.

Journalists and photographers from TV, radio and newspapers are waiting at the cordon trying to get information.

The New York City Police Department is expected to hold a news conference shortly on the incident in Brooklyn, though an exact time has not been announced.

If you're just joining us, here's what we know so far:

•At least 13 people have been injured, including at least five from gunfire.

•The incident took place at a busy subway station at 36th Street and 4th Avenue during rush hour.

•Firefighters at the scene were initially responding to reports of smoke on a train. Once there, they found gunshot wound victims.

•Police say there are no active explosive devices at the scene.

•No arrests have been made. Initial reports suggest the suspect was wearing an orange construction or Metropolitan Transportation Authority vest and possibly had a gas mask.

•Local authorities have urged the public to stay away from the scene, which has been swamped with police and emergency crews.

Harry Low
Reporting from Brooklyn

As you might imagine there are clusters of police, firefighters and paramedics at the scene. I've just seen FBI agents arriving too.

Warning: Some readers might find the photo below distressing

Lots of pictures have been emerging on social media showing the chaotic aftermath of the shooting at 36th Street station in Brooklyn. Some of them show gunshot victims, and pools of blood on the floor.

Here's a picture verified by the Reuters news agency:

Image source, Reuters

The BBC's New York bureau chief, John Mervin, has reported a 'huge' presence of police and emergency response vehicles in the area, blocking large swathes of an important Brooklyn thoroughfare.

The vehicles have reportedly cut off access to several blocks full of 4th Avenue, a major six mile (9.7km) thoroughfare that stretches from Downtown Brooklyn to the Belt Parkway in Bay Ridge.

Bomb squads are also at the scene.

A police source at the scene reported that a preliminary description of the suspect is that he's approximately 5'5 (165cm) and wearing an orange construction or Metropolitan Transportation Authority vest.

Rain has begun to fall in the area, sending some curious onlookers scurrying away.

New York police, the fire department and the FBI are at the scene of a shooting in Brooklyn.

At least 13 people have been injured in the incident, which happened during the morning rush hour at a subway station.

The White House press secretary has tweeted that President Joe Biden has been briefed on the situation in New York. President Biden is meant to travel to the state of Iowa later today.

The US federal government's Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) says it has deployed in support of New York's police department at the scene of the shooting incident in Brooklyn.

The ATF announced no further details of the investigation being carried out by its agents.

Specialist units within the ATF receive training in arson and explosive incident investigations.

John Mervin
New York bureau chief, at 36th street station

I'm standing at the cordons right at the entrance of 36th street station. The subway lines in New York are quite shallow compared to other cities and 4th Avenue runs along the tunnel of the subway, and so we're standing right above the incident.

Officers from the New York Police Department suggest people are still being treated at the scene below us. They aren't able to give us timings of when they are going to release more information. For them this is very much an active scene and we are not getting much at the moment.

Image source, EPA

New York City’s mayor’s office and the state’s governor both say they are closely following the situation in Brooklyn and have urged the public to stay away from the area.

In a post on Twitter, Fabien Levy, press secretary for NYC Mayor Eric Adams, said that the mayor is already being briefed about the situation.

“While we gather more information, we ask New Yorkers to stay away from this area for their safety and so that first responders can help those in need and investigate,” he said.

New York state mayor Kathy Hochul said that state authorities will work with the city’s Metropolitan Transportation Authority (MTA) and city police to provide further updates as they become available.

Police in New York City say they are investigating a shooting that has left at least 13 people injured at a Brooklyn subway station.

According to New York’s fire department, firefighters first responded to the 36th street station in Sunset Park around 0830 local time (1330 GMT) following reports of smoke.

First responders at the scene found gunshot victims and unexploded devices at the scene. It is unclear what type of devices were found.

Police have now said that there are no active explosive devices at the station.

Citing an unnamed law enforcement official, the New York Times is reporting that police are seeking a man with a gas mask and wearing an orange construction vest.

Follow here for more updates as this story develops.