Footage captured by CCTV show kids loitering on railway lines or taking pictures on crossings.
The series of films were taken at locations near Charfield, South Gloucestershire, Wantage in Oxfordshire and Toffles in Devon
The rail operator published the footage as part of a campaign to warn the public about the dangers of rail tracks during the half term holidays.
Andy Phillips, Network Rail programme manager for route crime, said: “Incidents of trespass on the railway cause issues for everyone using the network, where an individual could sustain life-changing injuries and in the worst-case scenario, loss of life.
“It is disappointing to see young people ignoring the dangers of level crossings.
“We are proactively working with British Transport Police to make people aware of these dangers and measures have been put in place to tackle the issue, including additional signage and gates, installing cameras, and hosting educational events.
“We sincerely urge people to stay off the tracks and ensure they understand the risks of trespassing. Anyone who witnesses any trespass incidents is encouraged to report what they’ve seen to BTP via the text service on 61016.”
Network Rail say that the children seen in the footage could have been struck by a train or even electrified – leaving them with potentially life-changing injuries.
Andrew Morgan, British Transport Police Superintendent, said: “Trespassing on the rail network is extremely dangerous and can result in life-changing injuries or, in some cases, loss of life.
“It’s important children and young people understand the railway is not a playground – it is full of hidden dangers and also a criminal offence to trespass”
“As with all school holidays, we always increase our patrols, looking proactively for those breaking the law.
“I would urge parents and guardians to have conversations with their loved ones about the dangers of trespassing on the rail network.
“I would also urge members of the public who witness anyone trespassing to let us know by texting us on 61016 or calling 0800 405040. In an emergency you should always call 999.”
