Aussies among Thai train injured

Foreign tourists including Australians were among 23 people injured when an overnight sleeper train derailed in Thailand, the national rail operator says.

The Bangkok-Chiang Mai express service was carrying nearly 300 passengers when seven carriages came off the tracks in the northern province of Phrae early today, according to the State Railway of Thailand.

Eighteen foreign tourists suffered minor injuries, including visitors from Australia, France, Spain, China, Japan and the United States, as carriages toppled onto their sides.

"Derailments happen quite often," said State Railway of Thailand governor Prapat Chongsanguan, adding that the tracks were in the process of being upgraded.

"Initially we think that this time it's due to old rail track."

Services on the route were suspended for the day.

Safety standards are generally poor in Thailand and road traffic accidents are also common.

Thailand's cabinet in March approved a plan to spend $US68 billion ($74 billion) on a high-speed railway and other transportation mega projects to drive the nation's economic development.

Under the seven-year scheme, which has yet to be approved by parliament, 200 high-speed trains will whizz across the kingdom on four lines linking the capital Bangkok with the north, south and east of the country.