Trains have been delayed in South East England because of thieves stealing electrical cabling from railway tracks for its scrap value.
Sharing details of an incident on twitter, British Transport Police (BTP) officers in Essex said they are "working hard to reduce disruption to your journey".
The tweet featured photos showing large amounts of stolen cable that had been seized by officers.
They said that the thefts affected the c2c services, which serve East London and Essex, and the Greater Anglia network, which covers Cambridgeshire, Suffolk and Norfolk and parts of Hetfordshire.
The tweet reads: "Delays on c2c Rail and Greater Anglia can be caused by thieves stealing railway cable.
"Sold as scrap, it's stripped down and untraceable.
"Yesterday we had to call in Network Rail Anglia to help us seize all the stolen cable we found. We're working hard to reduce disruption to your journey."
Network Rail's website says: "Cable theft costs us millions of pounds each year. The total cost to the economy – taking into account the impact of freight delays to power stations and supermarkets, and on passengers who miss appointments or have their day ruined – is even higher.
"The theft of metal is a big problem for the railway as thieves target signalling cables, overhead power lines and even metal fences to sell for scrap.
"Britain's rail network is designed to fail safe, which means that when a cable is cut trains are brought to a standstill. This protects passengers but can lead to lengthy, frustrating delays while the problem is found and fixed safely.
"A large proportion of our funding comes from the Government, so these thefts are, ultimately, costing taxpayers money."
"We have done a huge amount of work to tackle cable theft including:
- funding British Transport Police officers
- using CCTV to alert us that people are on the network and to support the police
- installing new ways of securing cables
- using forensic marking agents
- introducing cables which are harder to steal and easier to identify
- and setting up a dedicated security team.
"Together with other essential infrastructure providers we successfully lobbied the Government to introduce the Scrap Metal Dealers Act 2013.
The Act means that:
- Scrap metal dealers must be licensed and local authorities have the power to refuse unsuitable applicants and revoke licences
- Police have the power by court order to close unlicensed scrap yards
- All sellers of metal must show verifiable ID which dealers must record and retain
- Cash trades for scrap metal are illegal without exception and subject to unlimited fines
- A public national register of scrap metal dealers has been created.
"This will help make sure that sales of scrap metal are accounted for and that all people trading scrap are doing so legitimately.
"You can help by reporting suspicious behaviour on the tracks to the British Transport Police:
- 0800 40 50 40
- Text 61016
- In an emergency call 999
