LONDON : British Transport Police said Friday it was responding to reports of a train "collision" north of London, with other emergency services saying they were attending to the incident amid media reports of injuries.

"We're responding to reports of a collision involving two trains in the Bedford area," the transport police force said on X, referring to a market town around 56 miles (90 kilometres) north of the capital.

Unverified footage posted to social media appeared to show two East Midlands Railway (EMR) trains having collided, with one running into the other, and passengers pictured standing on the tracks beside damaged rail carriages.

The trains appeared to have remained upright on the track, according to the images posted.

"Emergency services are dealing with an incident between London St Pancras and Leicester," EMR said on X, without providing further details.

East of England Ambulance Service said on social media it had sent "a number of resources, including air ambulance and our Hazardous Area Response Team, to a major incident on the railway south of Bedford".

Meanwhile Bedfordshire Fire and Rescue Service said its "crews are currently in attendance at an incident on the railway just south of Bedford."

The Daily Telegraph and TalkTV were among British media outlets to report passengers had been injured in the incident.

But the emergency services were yet to provide any details about injuries.

Transport Secretary Heidi Alexander said she was "deeply concerned" by the collision reports.

The rail operator Thameslink, which also serves the region, said on its X account that "all lines are blocked between Luton and Bedford... due to a problem under investigation".

Train collisions are relatively rare in Britain.

In September 2023, several people were injured after two trains collided at Aviemore railway station in the Highlands of Scotland.

The crash happened on the Strathspey Railway, a heritage railway run separately from mass-transit public services, and involved a stationary carriage and another train in the station.

One of the trains involved was the record-breaking, century-old Flying Scotsman, the first steam train to reach over 100 miles an hour, the National Railway Museum said.

In August 2020, an early morning service from Aberdeen to Glasgow came off the tracks, killing three people near the town of Stonehaven, northeast Scotland, after a landslip caused by heavy rain.

The driver of the train, a conductor and a passenger died and six other people were injured in the tragedy.

Network Rail -- an arm of the UK Department for Transport -- pleaded guilty in 2023 to safety failings at a court hearing and the public body was fined £6.7 million ($8.4 million).