The BBC's John Thorne: "A two-year-old child suffered severe head injuries"

Inspector Ken Short, of Northumbria Police Motor Patrol South, said the two women who died were waiting on a bus depot seat inside the station.

They were hit and then dragged underneath the bus.

The driver was also taken to hospital and is said to be in deep shock.

It is not yet known what caused the bus to go out of control.

A two-year-old child suffered serious head injuries and was taken to the city's hospital.

Speaking from the bus station, where safety barriers were strewn across the concourse, many witnesses were close to tears as they spoke of their horror at the carnage.

People were trapped under the wheels

John Lamb, 68, of Hendon, Sunderland, who helped comfort one injured person until paramedics arrived, said: "I heard a massive smash and when I looked around the bus just ploughed through the bus stop. I ran to see what I could to do and saw a woman and a young child under the wheels.

"I held one woman's neck to keep her steady and she was bleeding heavily."

Temporary Divisional Officer Alan Brown, of Tyne and Wear Fire Brigade, who was at the scene, said: "The crews were very distressed by what they encountered. Just imagine a packed bus station and a bus careering through it.

"It was a horrendous experience for everyone at the bus station and anyone would find such an incident distressing."

Staff from the Vehicle Inspectorate have visited the scene and are working closely with the Police Accident Investigation Team.

Inspector Short, who is leading the investigation, said: "There were a number of eye witnesses to the accident and it will have been very distressing both for them and for the emergency services who had to deal with it."

He said that the knock-on effect for traffic in the city would be "horrendous" as several roads had been closed while police investigated the incident.