Police and V/Line are appealing for public information after train tracks were allegedly tampered with at Terang earlier this week.
A Warrnambool bound service struck several wooden sleepers that were placed across the track about 8.20pm on Tuesday.
There was no damage to the train and the service continued without major delay.
The incident reoccurred when the driver of the next Warrnambool bound service reported striking an object at the same location in Terang about two hours later.
The Wednesday 1.05pm service to Warrnambool also struck the sleepers.
Again, there was no damage to the trains and the services continued, however there were delays.
Vandals are also believed to have interfered with signalling equipment which caused the continuous operation of level crossings in the Terang area on Tuesday night.
V/Line has implemented additional security measures as a result.
Victoria Police were notified on all occasions and are assisting V/Line with their investigation.
A V/Line spokesman said the "illegal behaviour on the Warrnambool line earlier this week was extremely dangerous".
"It could have led to a serious derailment, causing serious injury or death," he said.
A police spokesperson said VLine and Victoria Police were appalled by the "reckless behaviour" and requested anyone with information to come forward.
"Members of the public with information about this incident are invited to contact Terang Police or Crime Stoppers on 1800 333 000," the spokesperson said.
"If you witness dangerous behaviour around trains or public transport please call Triple-0 immediately. Please do not call your local police station as this will delay police responding to the incident."
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