Multiple tourists were killed and others injured Friday when a bus carrying more than 50 sightseers home from a visit to Niagara Falls crashed in New York state, officials said.

Police said many of the passengers heading back to New York City were of Indian, Chinese and Filipino descent.

State police spokesman James O'Callaghan told reporters the bus had traveled to Niagara Falls, on the border with Canada, for the day and was heading home when the accident took place east of Buffalo.

"For unknown reasons, the vehicle lost control, went into the median, overcorrected and ended up in the ditch," O'Callaghan said.

"This bus was going full speed. It did not hit any other vehicle."

The police spokesman said people were still trapped in the wreckage, while others were ejected on impact. Images broadcast on local television showed the heavily damaged bus on its side.

Translators were sent to the scene to help communicate with the victims.

At least one child was among the dead, the spokesman said, without offering a specific death toll.

"There are many serious injuries, and as was just announced by New York State Police, there are multiple fatalities," Erie County Executive Mark Poloncarz said on X.

At least 21 people were taken to Erie County Medical Center, a hospital official told AFP.

'Heartbroken'

Eight helicopters were involved in the rescue effort, Margaret Ferrentino, president of Mercy Flight, a nonprofit provider of air ambulance services, told AFP. 

"The driver is alive and well -- we're working with him. We believe we have a good idea of what happened, why the bus lost control. We just want to make sure that all the details are thoroughly vetted," O'Callaghan said.

State Governor Kathy Hochul said her team was coordinating with state police and local officials "who are working to rescue and provide assistance to everyone involved."

"I'm heartbroken for all those we've lost and all those injured and praying for their families. Thank you to our brave first responders on the scene," said the senior US senator from New York, Chuck Schumer.

Niagara Falls -- towering waterfalls that span the US-Canada border -- is a popular tourist destination.