A double-decker bus carrying municipal workers on a field trip in western Thailand plunged off a steep road and into a ravine, killing at least 30 people and injuring 22 others, officials said Tuesday.
The accident Monday night (overnight NZ time) was the latest fatal crash on a mountain road in Tak province known for its treacherous dips and turns where 300 accidents occurred last year, said provincial governor Suriya Prasatbunditya.
The road is frequented by buses and trucks traveling to and from the border with Myanmar.
The driver was trying to pass cars on a winding downhill road when it skidded off the edge and flipped several times as it tumbled about 30 metres into a valley before crashing into a tree, Suriya said, recounting what other drivers who witnessed the accident told police.
The driver, who survived the accident with a broken rib, said he tried to slow down but claimed the brakes stopped working, Suriy said.
The bus was one of four carrying local workers and villagers Monday night from Tak to northeastern Thailand.
''Accidents happen on this road very often,'' Suriya said.
''We've put warning signs up to caution road users but the accidents keep happening.''
Road accidents are common in Thailand, where safety standards are poor and road rules are rarely enforced.
Last year, more than 8600 people died in accidents on Thai roads.