Railway passengers were thrown from their seats when a train "sped through Cambridgeshire 50mph over the speed limit".

The government's Rail Accident Investigation Branch (RAIB) is investigating the incident, when a Lumo train reportedly travelled through Peterborough station at 75mph.

The speed limit was set at 25mph, and the sudden movement of the train caused luggage to topple from the overhead compartments.

British Transport Police said 15 passengers sustained minor injuries, and paramedics offered them assistance when the train came to a stand nearby.

The train is said to have sped through Peterborough at 10.20am on Sunday, April 17.

It left Newcastle station at 8.20am and was travelling to King's Cross.

A RAIB statement read: "The service, operated by Lumo, passed over three sets of points at the north end of Peterborough station at a speed of 75mph.

"The was above the maximum permitted speed limit for these points of 25mp.

"Passing over the points at this speed meant that the train suddenly lurched sideways.

"The sudden movement of the train resulted in some passengers being thrown from their seats."

The RAIB statement added that the train did not derail, and there was no damage to railway infrastructure or the train involved.

The train was not due to stop at Peterborough, and RAIB has already established that the train was originally due to travel through Cambridgeshire on the "fast" lines, but it was transported onto the slower lines, where the speeding incident occurred.

Investigators will look at a range of factors, including the nature of reported injuries, management factors, the signalling system and the actions of the driver.

A Lumo spokesperson said: "At Lumo, the safety of our customers and staff is our highest priority, and we will be co-operating fully with the RAIB’s investigation.

"Until the investigation has concluded it would not be appropriate to comment further.

"In the meantime, we remain committed to providing the highest standards of service to our customers."

FirstGroup launched Lumo in October 2021, and trains currently call at London King's Cross, Stevenage, Newcastle, Morpeth and Edinburgh Waverley.

It does not receive government money and markets itself as a low-cost rail operator in competition with airlines.

RAIB said it will publish its findings at a later date.