Police are investigating after a bike apparently dumped on the Deal to Dover railway line was hit by a train.
British Transport Police today said passengers' lives could have been put at risk in the incident.
It happened at just after 9am on Sunday when the Ramsgate-bound train hit the bike about three miles from the Martin Mill station. The train was forced to stop as the driver raised the alarm.
A Southeastern train. Library picture
A BTP spokesman said officers were continuing their enquiries to find out how the bike came to be on the tracks.
She said: "It's still early stages in this case as we have yet to determine whether the bike was placed deliberately onto the line.
"However, whilst deliberately placing objects onto the railway line may seem like fun to those who commit such offences, what they don't realise are the potentially serious consequences of their extremely foolish behaviour.
"Trains travelling at high speeds risk being derailed by objects on the line, which puts passenger’s lives in danger.
"Police treat incidents where the line has been obstructed very seriously, and will seek to pursue offenders through the courts."
Anyone with information is asked to phone British Transport Police on 0800 40 50 40 or text 61016, quoting 125 of 13/10/2013.