A 16-year-old boy's hand was trapped in the internal doors of a moving train.

Adam Braggs was trying to walk between carriages on an Electrostar, one of Southern Trains £856 million new rolling stock, when the door slammed on his fingers.

It took the strength of his mother Julie and two other passengers to prize the door open.

Mrs Braggs, of Hallyburton Road, Hove, was shocked to see her son's hand swell up.

She said: "Adam pressed the button and the door opened and then slammed shut so fast on his hand. I couldn't believe how hard it was to open the door. If that had been a toddler their fingers would have been hanging off.

"It's put the fear of God in me about my younger children going on the trains. I prefer the old slam door ones now, or I'll take the bus. We are going to walk to the hospital first to get Adam's hand looked at."

Mrs Braggs is the latest passenger to complain about the trains brought in to replace the outdated slam-door trains and update the rail network with modern, safer and more efficient carriages.

Complaints have included problems of sliding doors closing as parents tried to board carriages and toilets locking when tanks are full.

Earlier this month, mother Madeleine De Angelis watched her nine-year-old son carried away on a train when the doors slammed shut before she could get on.

Two more passengers have since contacted The Argus to complain about the automatic sliding doors.

Emma Harris, 24, from South Heighton, near Newhaven, was getting off a train at Newhaven station when the doors closed on her six-week-old baby's pram.

Another passenger, who was also travelling with a six-week-old baby, managed to help her free the pram but was trapped on board when the doors closed.

Ms Harris said: "She ended up being taken to Lewes.

"She had helped me and got back on to get her own baby. As soon as the doors shut the train just left.

"There was no conductor to check if there were any problems.

"They should certainly be looking at safety on the trains."

Jeanette Stringer, from Burgess Hill, wrote in after reading about Mrs De Angelis's story.

Her 12-year-old son was trapped on a train at Burgess Hill station.

As he followed her off the train he dropped some money and stooped to pick it up. As he reached for it the doors closed.

Mrs Stringer just had time to tell him to get off at the next station before the train left.

She then drove to Wivelsfield station and was relieved to find him waiting there.

She said: "What happens if a child's coat gets caught in a door?

"A spokesman from Southern Trains said he doubts it is a safety issue. I hold him responsible when someone dies."

Southern Trains has spent £856 million on 700 new carriages.

It has enhanced safety features, passenger information systems and facilities for people with disabilities.

A Southern spokesman said: "The doors have been passed by Her Majesty's Railway Inspectorate. There are also mirrors for the drivers to see when there are problems.

"We can't legislate completely and have everything 100 per cent safe all the time. As far as we are concerned, the trains are as safe as can possibly be."