A helicopter has smashed into a highway in California, leaving at least three people with critical injuries.

According to the Sacramento Fire Department, the helicopter crashed onto the eastbound Highway 50 near Howe Avenue.

It is believed the aircraft was a Reach helicopter which is used to provide air medical services - although it is not yet known if it was travelling to or from a hospital.

PICTURED: The Sacramento helicopter crash, as it happened

Footage circulating on social media shows the moment of the crash, as captured by a driver.

In it, the helicopter appears to hit something before smashing down onto the road below.

Further video shows legions of emergency vehicles at the scene as smoke billows from the downed craft.

Sacramento Mayor Kevin McCarty has confirmed that survivors are all being treated in local hospitals.

GB News has reached out to the Federal Aviation Administration. for more information.