A passenger train was derailed in the mountains of northern Thailand early Wednesday, leaving nearly 30 people hurt, including foreign tourists.

Around 300 passengers were on board the overnight train from Bangkok to Chiang Mai when it skidded off the tracks in the northern province of Phrae.

None of the passengers were killed but at least 23 people – including 18 tourists – suffered minor injuries as carriages toppled to their sides.

Train services between Bangkok and Thailand’s largest northern city, Chiang Mai, were disrupted for at least a day after the derailment.

Railway authorities believe the accident was caused by old tracks that were scheduled for repair, Jakarta Post reports.

Officials also acknowledged that the country’s train network is suffering from poor maintenance and old age; some parts are more than a century old, and they are exposed to heavy rainfall and erosion.

“From an initial investigation, the train was traveling under its limit, but the tracks at that stretch were old and in poor condition. The last carriage, therefore, skidded and brought down other cars,” State Railway of Thailand governor Prapas Jongsanguan told The Associated Press.

The Bangkok-Chiang Mai train is popular among foreign tourists, according to the Wall Street Journal.