Two newlywed couples, four sisters from one family and two brothers from another were among the 20 people killed when a limousine taking passengers to a surprise birthday party crashed in New York on Saturday.

The collision was the deadliest US transport accident since a 2009 plane crash in Buffalo, New York that killed 49 people, Robert Sumwalt, chairman of the National Transport Safety Board (NTSB) said.

Officials have not released the victims' names but some of their identities were confirmed through local media reports and GoFundMe pages.

A group of 17 had climbed into the stretch limousine to celebrate their friend Amy Steenburg's 30th birthday at a popular tourist spot in upstate New York, according to the Times Union of Rochester, New York.

Steenburg, her three sisters Mary Dyson, Allison King and Abby Jackson, her new husband Axel Steenburg and his brother Rich Steenburg all died in the crash, relatives told The New York Times.

Erin and Shane McGowan, a recently married couple, were also killed.

"She was a beautiful, sweet soul; he was, too, they were very sweet," said Valerie Abeling, Erin's aunt.

"They were two very young, beautiful people."

The limo was heading to an upstate New York brewery, officials said.

It passed through an intersection without stopping, hit an empty parked car and then crashed into two pedestrians.

Eventually the vehicle came to rest in a shallow ravine and at least six ambulances, two helicopter units and three fire companies responded to the emergency.

All 17 passengers, the limo driver and the two pedestrians were killed, NTSB officials said.

The site of the accident is a danger spot that has long worried locals said Jessica Kirby, the managing director of the Apple Barrel County Store which sits at the intersection.

She added that three tractor-trailers had run through the same stop sign that the limo had and had crashed into the field behind her business.

"More accidents than I can count," she said in an email to the Associated Press.

"We have been asking for something to be done for years."

Andrew Cuomo, New York State's governor, said that he had "directed state agencies to provide every resource necessary to aid in this investigation and determine what led to this tragedy", in a statement released on Sunday.