Police and fire brigade at the scene. Pic: @GreenPeterU

A major emergency procedure swung into action when an aggressive passenger threw what was assumed to be a dangerous chemical onto the carriage floor of a train travelling through Lewisham on Sunday morning.

The train was immediately halted and dozens of passengers evacuated onto the tracks just outside Honor Oak Park station. Police and other emergency services rushed to the scene, assuming some kind of terrorist or criminal incident involving a lethal substance. National Rail cut the power supply on the line from East Croydon to London Bridge, which resulted in delays, suspensions and cancellations to other services.

However, there was much relief all round when the feared dangerous chemical turned out to be….a bottle of olive oil.

Police are now investigating the chain of circumstances that led to the incident and to identify the passenger who had been behaving aggressively to others. A spokesman for British Transport Police said: “Shortly before 9am on November 25, officers were called to Honor Oak Park station in south London after reports of a passenger causing a disturbance. It is believed a man was hassling passengers and then poured what is believed to be olive oil on the floor of the carriage.”

The spokesman added: “A number of enquiries are being made to understand what happened and who poured the liquid.” No-one has been arrested.

Fire officers at Honor Oak station the scene. Pic: @GreenPeterU

One of the passengers, Peter Underwood, tweeted: “Stuck on a train into London Bridge because someone spilt some ‘liquid’ over the floor and then left the train. Everyone safe, just waiting for emergency services to arrive and check things out.”

Underwood and all other passengers were forced to disembark onto the tracks at around 10:15 am; they were then forced to continue their journey using bus replacements or other rail networks.

To allow the evacuation, National Rail were forced to switch off the electrical power supply between East Croydon and London Bridge.

Thameslink said: “To allow the emergency services access to the train, power to the electrical third rail on the track was turned off, and as a result, the line was closed to all other trains.” Cancellations and train delays on the Thameslink network, and the London Overground network, from West Croydon towards New Cross were also affected.

London Overground are currently suspended between New Cross Gate and West Croydon; Thameslink services into London from Bedford or Peterborough will be terminating early; Southern services between London Bridge and Crystal Palace are currently suspended #EastCroydon

— National Rail (@nationalrailenq) November 25, 2018

Some trains terminated short of their destination and Southern services between London Bridge and Crystal Palace were suspended.

London Overground and Thameslink re-opened all affected routes later in the day.

Anyone with information should contact BTP by sending a text to 61016 or by calling 0800 40 50 40 quoting reference “136 on 25/11/2018.”