Bangkok (AFP) - Thailand's football authority has been fined US$30,000 (S$42,983) after fans lit dozens of flares in the stands to celebrate last month's Suzuki Cup triumph over Indonesia.

The scenes, which saw thick plumes of pink smoke blanket crowds at Bangkok's Rajamangala stadium, marred the War Elephants' December 17 Cup win and resulted in a disciplinary hearing.

In a statement on Thursday, the Football Association of Thailand (FAT) said it had agreed with regional body the Asian Football Confederation to pay the US$30,000 penalty.

Pathit Supapong, a spokesman for FAT, said Thailand had been warned it would face harsher sanctions if fans light flares again at an international match.

"The penalty will be higher than just a fine," he said.

Thai police have arrested a man for selling flares but have yet to arrest any fans for lighting them at the second leg of the final in Bangkok, which Thailand won 2-0.

The flares came from the end occupied by Thailand's "ultra" fans - an increasingly rowdy presence at international games.

Authorities are trying to curb the rising use of flares, fireworks and smokebombs inside stadiums around the world, abandoning matches, fining teams and deducting points.