Officials say a car bomb has exploded at a shopping mall on a Thai island popular with foreign tourists for its pristine beaches, injuring seven people.

Samui Island's disaster prevention and mitigation chief Poonsak Sophonpathumrak said the bomb was hidden in a pickup truck, and that it went off late Friday night on the basement level of the hopping Central Festival mall after a fashion show.

Poonsak said authorities believe the vehicle was stolen from one of the three southern Thai provinces plagued by violence. More than 5,000 people have been killed since an Islamic insurgency began in the sub-region in 2004.

Samui, in the southern province of Surat Thani, is one of Thailand's top island destinations.