Unidentified miscreants allegedly pelted stones at the recently launched Vande Bharat Express train on Monday when it was passing through an area between Thirunavaya and Tirur in this northern Kerala district.
The incident took place around 5 PM in the evening and Railway officials alerted the local police about it.
Police said the train continued its journey to Thiruvananthapuram and no one was injured.
"We were alerted by the railway officials. The investigation is on to trace the miscreants," police told PTI.
As per preliminary reports, the stones left minor scratches on some window panes of the train.