A six-year-old boy and his mother were among three pedestrians mown down on a pavement by a suspected drink driver.

The boy lay screaming "Help me, help me " as his mother and a man lay unconscious and bleeding at his side.

A motorcyclist was also hit by the car, leaving him with horrific leg injuries.

The driver of the car was arrested on suspicion of dangerous driving and drink driving at the scene.

Witnesses described "carnage" after the crash and told how they tended to the injured as they lay sprawled on the pavement.

The force of the impact launched the boy's trainers off his feet and into nearby gardens. One was found on the roof of a 10ft porch.

The youngster was walking with his mother and a man along Irvine Road, Littlehampton, on Saturday morning when they were hit by the silver Citroen Saxo.

The car mounted the pavement after colliding with a Triumph motorcycle at the junction of Irvine Road and Beach Road, at about 10.50am.

The car hit the three pedestrians, who are believed to have been on a day trip to the seaside town, and ploughed into the garden wall of a nearby house.

Neighbours ran into the street to help and police, paramedics and fire crews from Littlehampton attended the scene.

The Sussex Police helicopter landed in the Marina Gardens opposite Irvine Road and airlifted the male pedestrian to Southampton General Hospital with life-threatening injuries.

Last night doctors said he was in a critical but stable condition.

The male motorcyclist, believed to be in his 50s, had serious leg injuries and was airlifted to Worthing Hospital by the Sussex Air Ambulance helicopter.

His condition is also stable.

The female pedestrian suffered head injuries and her son had broken his leg.

Both were taken to St Richard's Hospital in Chichester by ambulance and are stable.

The driver of the car, a 24-year-old Littlehampton man was uninjured.

He was seen using his mobile phone after the smash and heard by one witness to say "I've done something really bad now."

Eyewitnesses said the car travelled over the junction and into the oncoming motorcycle.

Natalie Stilwell, 25, of Beach Road, said: "I heard an almighty crash so I ran out.

"There were people shouting and trying to help, the little boy was crying for his mum but she was unconscious.

"I ran to the motorcyclist who was trying to stand up but his leg was badly injured.

"It was horrible. I just hope everyone is going to be okay."

Part of the garden wall of Harry and Norma Robinson's house in Irvine Road was smashed down as the car crashed into it.

It is the third time the wall has been knocked down by a car in the last three years.

It was only a week ago that they finally had the £200 excess for the last accident returned by their insurance company.

Mr Robinson said: "There's a blatant disregard for speed down Beach Road. It's horrifying how fast people drive down there. It won't be long until someone dies.

"Irvine Road is used as a rat-run. There are always accidents at the junctions along it and this particular one is an accident blackspot.

"We need traffic calming such as speed limit signs and speed bumps. Something has to be done before someone gets killed."

Norma said: "Some of these youngsters who drive too fast should go to an accident and emergency unit for a day and see what happens to people in car crashes.

"They would be horrified and maybe it would slow them down."

Police have appealed for witnesses to contact them on 0845 6070999, quoting Operation Durrow.