Two people were hospitalised on Saturday after the helicopter they were flying in crashed into the ocean off a beach in the US state of Florida.

Miami Beach police said on Twitter that they received a call about the crash at 1.10pm (6.10pm GMT). “Police and @MiamiBeachFire responded to the scene along with several partner agencies,” the tweet said. 

“There were three passengers onboard. Two were transported to the hospital,” police said, adding the two were in “stable condition.”

A video posted alongside the tweet shows a helicopter falling into the Atlantic Ocean, not far from people swimming or sunbathing on the crowded beach.

Mary Schiavo, the former inspector general of the US Department of Transportation, said on CNN that the video showed the helicopter appearing to lose engine power.

“There were two important things at work here,” she said. “One, the pilot was trained… And two, was able to maintain some control of the aircraft because it appears that once you lose your engines, you have nowhere to go but hopefully a controlled trajectory down.”

She said that watching the video, it appeared the pilot was able to steer away from beachgoers even as the helicopter fell.

The FAA told CNN in a statement that the helicopter crashed under “unknown circumstances”.

The aviation authority said it would investigate the accident along with the National Transportation Safety Board.