At least one person has been killed and 37 others have been injured when a car rammed into a crowd in Las Vegas, Nevada.

According to police, the incident occurred on the Las Vegas Boulevard at around 7 p.m. on Sunday, when a vehicle drove up onto a sidewalk and hit a large group of people.

"Everyone was running ... and as I was running, I saw a car up on the sidewalk coming toward us," a witness told CNN affiliate KLAS.

"I saw a lady, she didn't seem like she wanted to stop the car, she had both hands on her wheel and she was looking straight forward."

Police have cordoned off the area in front of the Paris Hotel & Casino and Planet Hollywood, where a beauty pageant was being held.

The driver was detained by police, according to local TV networks.

The woman is undergoing various tests, including one for alcohol, authorities said.

At least seven of the victims are said to be in critical condition.

Authorities have said the woman may have intended to hit the crowd but so far ruled out any terror links.