TWO boys remain in a serious condition in hospital after a rollercoaster ride derailed at a popular Lanarkshire theme park.

The youngsters are currently being treated at the Royal Hospital for Children following the horror crash which happened on Sunday at 3.40pm at M&Ds theme park within Strathclyde Park, Motherwell.

One of the victims, who is 12, is being treated for chest, abdominal and leg injuries while an 11-year-old boy is currently receiving treatment for arm and hand injuries.

The boys are among several injured after five gondolas attached in a train in the Tsunami inverted rollercoaster, detached from its rails at a bend, collided with the ride's main structure and fell to the ground.

There were nine passengers on board including two 19-year-old adults and seven children. Three are aged 11 and the others are aged, 12, 13, 14 and 16.

The passengers were immediately given medical attention and taken to three hospitals for treatment.

The Royal Hospital for Children say an 11-year-old boy is in a stable condition after receiving treatment for leg and head injuries.

They also said a 13-year-old boy is being checked and is stable.

Wishaw General Hospital is treating a 14-year-old girl for serious chest injuries.

A 16-year-old boy who received treatment for an injury to his arm also remains in hospital.

The hospital has kept in an 11-year-old boy for observation and his condition is described as stable.

A 19-year-old girl was also treated for an injury to her wrist and has since been released.

A 19 year old man is being treated for a knee injury at Glasgow Royal Infirmary and is stable.

In addition, a 25-year old-woman who was passing-by the scene was also taken to Wishaw General Hospital for assessment but was released without any injuries. Police say the woman was not struck by the rollercoaster train.

Police officers secured the area and scene examination professionals were on site last night.

A joint investigation by Police Scotland and the Health & Safety Executive is underway.

The M&Ds theme park will remain closed until further notice.

Detective Inspector John Malcolm said: "This is a really serious incident that has affected many people visiting the theme park and our thoughts go out to those who have been injured.

"We have now launched a joint investigation with the Health & Safety Executive and our priority is to find out the cause of the incident.

"I would ask that anyone who witnessed the incident or indeed, anyone who may have video footage or photographs to get in touch with the dedicated enquiry team on 101."

HSE principal inspector Barry Baker added: “Our thoughts are with the children and adults who have been injured in this incident and I must give praise to the emergency services and members of the public who came to their aid so quickly yesterday.

"We have brought HSE specialists in mechanical engineering to the site this morning, to begin the process of finding out what caused the gondolas to come off the rails.

"HSE will work very closely with colleagues in the police as the investigation unfolds.”