Explosives planted by suspected Muslim militants went off at three locations in southern Narathiwat Province near the Malaysian border early on Monday wounding 27 people, police said.
The blasts, at the border town of Sungai Kolok, went off in near succession by parking lots of two hotels and at a discotheque, they said.
Two of the blasts came from improvised explosives stashed in fuel tanks of motorcycles abandoned at the parking lots.
There was no immediate claim of responsibility for the blasts.
The organization of the militants in the former sultanate annexed by predominately Buddhist Thailand a century ago remains murky and nobody claims responsibility for the near daily gun and bomb attacks.
Since July, security forces in the Malay-speaking region have launched almost daily raids on suspected insurgent hideouts and detained dozens of people without charge.