Emergency services are at the scene of a train derailment between Haywards Heath and Lewes in Sussex, Southern Rail has said.

Photographs circulated online show at least two carriages of a train lying on their side, with two passengers standing on top.

British Transport Police said: “Officers are currently on scene close to Lewes railway station following reports of a derailed train at 3.54pm today (13 August).

“We’re responding alongside paramedics and the fire service and will provide more information as soon as we can.”

In updates, Southern Rail said passengers who are currently on trains close to Lewes station should remain on the train and await further updates.

The rail operator said: “A train has derailed in the area between Haywards Heath and Lewes. Emergency services are making their way to the scene and we are working out the impact this will have on our network.

“At this time, no trains can run between; – Brighton and Lewes – Haywards Heath and Lewes – Seaford/Eastbourne and Lewes.”

Transport Secretary Heidi Alexander said she is “deeply concerned” by the incident and is “working quickly with the rail industry and local partners to assist passengers.”

The Rail Accident Investigation Branch (RAIB) said a team of inspectors has been sent to the scene.

Southern Rail advised passengers travelling to Gatwick Airport to give themselves an extra 150 minutes in order to make their flights.

The operator said replacement bus services had been requested from Haywards Heath and Lewes stations.