The driver of the bus also died in Friday morning's incident but has not yet been publicly identified.

Police said 58 people were involved in the crash on the Wirral - with many assessed at the scene.

Four children were taken to hospital and a 14-year-old boy is said to have life-changing injuries.

Other pupils were taken to an emergency services training centre in Wallasey, with 13 treated for minor injuries.

Calday Grange all-boys grammar school and West Kirby all-girls grammar school said one of its buses was involved in the incident - which happened just after 8am.

Police said children were on other buses that were travelling in convoy with the one that crashed.

All those involved will be offered trauma support and family liaison officers are supporting relatives.

The M53 remained closed in both directions between junctions 4 and 5 on Friday night, but authorities haven't yet commented on the possible cause of the crash.

Firefighters helped people off the bus - as well as stabilising the vehicle, said Mark Thomas from Merseyside Fire and Rescue.

Emergency services also declared a major incident due to the risk of multiple serious injuries.

"We sent a substantial number of ambulances, senior clinicians and our hazardous area response teams," said Joanne Clague, director for the North West Ambulance Service.

"A critical care doctor was also dispatched to the scene."

According to Calday Grange's website, the W3 bus route starts in the Chester suburb of Bache, making stops in Little Sutton, before joining the M53 on its route to West Kirby.

The bus that crashed is owned by Carvers Coaches in Ellesmere Port.