Twenty people died when a limousine ferrying guests to a wedding reception crashed  in a picturesque upstate New York town on Saturday.

The majority of those killed were travelling in the over-sized vehicle which police believe hit another car at speed outside a country shop in Schoharie, 170  miles north of New York City.  

At least two pedestrians were also fatally injured.

Captain Richard O’Brien of the NY state police department said emergency services were still trying to establish what happened.

He said: "This is a two-vehicle, multi-fatality investigation. It’s very preliminary. In it’s infancy stages. We have several units investigating."

Witnesses described hearing a loud bang around 2pm and a scene of horror outside the Apple Barrel Country Store with bodies scattered on the ground.

Bridey Finegan, a local resident, told a TV news reporter that rescuers had to pries open the SUV style limousine to get to the victims.

"I heard a loud bang, I came out my front door to see what was going on. I saw a lot of people here at the Apple Barrel out in the parking lot. Then I heard screaming, she said.

"Then I saw this large van, a very unusual looking vehicle out here in Schoharie in the bushes and really wrecked, hit a tree. 

"It looked serious because people were running back and forth. I saw one individual being taken by ambulance but they had trouble getting other people out."

Lester Andrews, 60, from Rochester, New York said his two stepsons and a daughter-in-law were among three of the people killed in the crash. 

The brothers, Axel Steenburg, 29, and Rich Steenburg, 34, and  Axel’s wife, Amy, also died in the crash, he told the New York Times.

“They rented the limo with some families and I don’t know exactly what they were doing. There’s just a lot of confusion, so many people died,” he said.

“Their mother is looking for some answers, he said. “She wants to know what happened to her sons.”

Jessica Kirby, 36, the manager of the Apple Barrel, said she believed multiple customers in the car park died when they were hit by the limousine as it sped down the hill at over 60 mph.

"I don’t want to describe the scene,” she added. “It’s not something I want to think about."