An airliner carrying 64 people crashed into the Potomac river after it collided with a military helicopter outside Washington DC.

The collision happened as the American Airlines flight from Wichita, Kansas, was approaching Ronald Reagan National Airport at around 21:00 local time (02:00 GMT) on Wednesday.

Authorities have not confirmed whether there are any casualties from the crash, but the BBC’s US partner CBS reported police saying that 18 bodies have been recovered so far, with no survivors.

Three US army soldiers were onboard the Black Hawk helicopter that collided with the jet, a defence official said.

It is unclear where the helicopter was coming from – although it belongs to a battalion based in Fort Belvoir, Virginia.

Multiple federal and local agencies are involved in the rescue mission.

At the scene, the BBC observed debris believed to be from the aircraft floating in the Potomac River. US media says the aircraft split in half when it crashed into the water.

Eyewitnesses told local media they saw sparks and flashes when the mid-air collision happened.

Ari Schulman told NBC Washington what unfolded before him quickly changed from “completely normal” to “very, very wrong”.

There was “a stream of sparks” underneath the jet. “It looked to me like a giant roman candle… I looked back to see a fireball,” he said.

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Asked at a news conference how many people have been rescued or recovered, Washington DC’s mayor Muriel Bowser said she could only confirm the number of passengers on each aircraft.

The city’s emergency chief John Donnelly said rescuers are battling cold, winds and darkness in the water.

“There is wind. There are pieces of ice in the water… and because there is not a lot of light, you are out there searching every square inch of space,” he said.

“These are very tough conditions for [rescuers] to dive in,” he added.

US President Donald Trump said he had been “fully briefed on the terrible accident”.

“Thank you for the incredible work being done by our first responders. I am monitoring the situation and will provide more details as they arise,” he said in a statement.

Takeoffs and landings have been halted at Washington National as emergency personnel respond to the incident, the airport wrote in a post on X.

Flights are being diverted to Dulles International Airport about 28 miles (45km) away, and the Washington DC metro system will stay open late to run extra trains to transport disembarking passengers into the city, said a spokesperson from the transport authority.

Federal aviation authorities and the US Congress have launched investigations into the incident.

American Airlines CEO Robert Isom said the airline has sent a team to Washington DC and he too will be travelling there.