An attempt by a group of young people to lift an East Coast Main Line level crossing barrier has been branded "incredibly dangerous" by Network Rail.
CCTV footage shows members of the group lifting the barrier in Rossington, near Doncaster, just moments before a high-speed train passes.
The group was caught on camera at the crossing in March.
Vicki Beadle, of Network Rail, said it was "extremely concerning and there could have been tragic consequences".
Network Rail, which manages the UK's rail infrastructure, urged parents to warn their children about the dangers of misusing level crossings.
Ms Beadle, the organisation's operations risk adviser, said: "Trains cannot swerve out of the way."
The group had been "totally oblivious to their safety", she said.
"Don't think you're invincible. The railway is a dangerous place to be around," Ms Beadle added.
East Coast Main Line trains travel at speeds of up to 125mph and more than one train may pass before the barriers are raised, according to Network Rail.
Insp Tony McGhin, of British Transport Police, said: "I cannot emphasise enough the potentially lethal consequences of acts like these."
A nearby crossing outside Rossington was temporarily closed in 2017 amid safety fears after images of children sitting on the railway line were released.
More about Network Rail's safety campaign on crossings can be found on its website.