TEHRAN: A bus plunged into a ravine in northern Iran early on Thursday morning, killing 19 people and injuring 24, the semi-official ISNA news agency reported.
According to the report, the accident happened in the northern province of Mazandaran.
The injured were taken to a nearby hospital and some were said to be in serious condition.
ISNA said the accident was caused by a technical failure in the brakes of the bus.
Iran has one of the world's worst traffic safety records, with some 17,000 annual deaths in road accidents.
The grave toll is blamed on wide disregard for traffic laws, unsafe vehicles and inadequate emergency services.