KUALA LUMPUR: A broken window on the Padang Besar-Butterworth KTM Komuter Utara service, which went viral on social media yesterday, was caused by vandalism, Keretapi Tanah Melayu Berhad (KTMB) has confirmed.

In a statement today, KTMB said Train No. 2951 was struck by an unidentified object thrown from outside about 6pm yesterday while travelling between Arau and Kodiang, shattering a window on the left side of its second coach.

"KTMB took immediate action after being alerted by the train driver, clearing the affected coach and restricting passenger access to it as a safety measure.

"KTMB auxiliary police personnel were also deployed to help manage passenger movement and ensure the situation inside the affected coach remained under control," it said.