The train hit a buffalo which was running down from the nearby mount. The wheel of one carriage was derailed. The accident caused a traffic jam for nearly four hours.
More than 50 rescue workers were sent to the site to put the carriage back to the rail. The train continued its trip at 4.15pm.
The derailment caused many North-South trains to be cancelled, said Bui Quoc Ty, manager of the Hoa Duyet railway station, where the accident happened.