The driver of a bus has died in a horrific accident in New Jersey that threw passengers across the road in a scene of chaos.

Onlookers rushed to offer first aid after two buses collided in Newark, throwing one of the vehicles in the air and causing it to split almost in half.

Officials said 19 people were injured, seven of them critically, in the accident between the number 13 bus - carrying 20 passengers - and the number 59 bus, which was empty.

Ras Baraka, Newark mayor, said: "We're praying for all of those in the hospital.”

During a news conference he said an investigation would focus on whether one of the buses had run a red light.

Witnesses described chaotic scenes as some victims were thrown across the road and more than 20 people needed to be pulled from the wreckage.

Two Starbucks employees rushed to help

“This is my city. This is Newark. … This is where we need to be," one employee told PIX11 news. "These people need help and we’re going to do whatever we need to do to help them.”

TV footage shot from a helicopter showed how one of the buses had crumpled in the impact with glass showering the ground.