A three-night operation has taken place across four counties in a bid to tackle metal thefts on the railway.
British Transport Police, accompanied by police dogs and a helicopter, have patrolled tracks in Essex, Berkshire, Buckinghamshire and Northamptonshire.
The action, supported by Network Rail, targeted a number of areas where cable theft has increased.
Cable theft results in delays to rail services and also affects homes and businesses, police said.
Supt Paul Brogden said: "Metal theft is not just an issue for the railway, it impacts on many other industries and communities as the criminals simply do not care who their behaviour affects.
"The theft of railway cable can - and does - result in lengthy delays and cancellations to rail service, whilst theft of other items such as residential earthing cable or communications cable can have a serious impact on people's homes and businesses.
"I want to send a clear warning now to all would-be cable thieves - not only are you risking your life, you stand a very high chance of getting caught in what is a highly-policed environment."