Bangkok: A car bomb has exploded at a shopping mall on the popular resort island of Samui, injuring about seven people on the eve of Thailand's new year holidays.

The island's disaster prevention chief Poonsak Sophonpathumrak told journalists the bomb was hidden in a Honda believed to have been stolen from one of three southern Thai provinces where an ethnic insurgency has killed more than 6000 people, many of them civilians, over the past decade.

Some 10 people were injured when a car bomb exploded in the basement of a shopping mall in the popular tourist resort of Koh Samui in Thailand overnight. Credit:Phuketwan

Islamic militants seeking a level of autonomy in the provinces bordering Malaysia have not previously targeted civilians in Thailand's tourist areas.

If the bomb is proven to be linked to the insurgency it would send alarm bells ringing through Thailand's security agencies only days after junta leader Prayuth Chan-ocha gave himself the powers of a dictator.