Bomb attacks could be politically-motivated - Thai police chief

He said most of the southern provinces, which were affected with the violent incidents, had backed the draft constitution during Sunday's referendum.

"Seeing from the sabotage plan and my past experiences, areas that accepted the draft constitution would be prone to these acts," he said.

Chaktip said the authorities had now proceeded to undertake legal action to nab the culprits.

He also said despite the fact that the improvised explosive device used in the bomb attacks bore striking resemblance with devises used by the southern Thai militants, the authorities could not draw conclusively and needed more investigations.

Bomb and arson attacks throughout the seven southern Thai provinces over the past 24 hours left four people dead and 35 injured, including 10 foreign tourists, said the Thai Police.

Two people died during twin bombing incidents in the coastal resort town of Hua Hin last night and this morning, while the other two, in bomb attacks in Surat Thani and Trang, this morning and yesterday.

In an earlier media conference, the Thai Police blamed "local sabotage" as the cause behind the violent incidents and ruled out any links to international terrorism.

Prime Minister Gen Prayut Chan-o-cha had also ordered security measures at public and tourist areas, including airports, to be tightened.