A chartered tour bus has reportedly lost control on downhill curve in Thailand's northeast and plunged off the side of the road, killing at least 18 people and injuring dozens more.

The Thai PBS television network reported on its website that in addition to the dead, 33 passengers were hurt in Wednesday night's accident in Nakhon Ratchasima province.

The report said passengers were returning to northeastern Kalasin province from a long-distance excursion to the seaside province of Chanthaburi, which borders Cambodia.

Statistics from the World Health Organization show that Thailand has the world's second highest rate of traffic fatalities after Libya.