Police on the Thai resort island of Phuket have found an apparent improvised explosive device in a pickup truck parked for two weeks near their station.

Police Major General Ong-art Puewruengnon said on Monday that two 15 kilogram cooking gas tanks were hooked up to a timer in the vehicle.

The explosive was discovered when police were clearing a parking area for year-end celebrations, Ong-art said.

"A bomb disposal team defused it and found that it was unable to explode," he said.

He said there was no indication who put the device in the truck, which had been parked since December 8 and discovered on Saturday.

Ong-art said the vehicle had been stolen in the neighbouring province of Songkhla from a man who was shot dead in May.

Thailand's deep southern provinces have been the scene of a Muslim insurgency since 2004, but the hostilities have not spread north to Phuket, which is popular with foreign tourists.

Muslim armed groups have waged a near-decade-long insurgency in Thailand's southernmost provinces but they are not known to have targeted Western tourists.

On Sunday, more than 20 people were wounded when a car bomb went off near a hotel in the southern province of Songkhla.

Shadowy insurgents have waged near-daily bomb and gun attacks, targeting security forces and civilians from both the Buddhist and Muslim communities in a conflict has left more than 5,700 people dead.

'Land of Smiles'

Tentative peace talks between the Thai state and representatives of the major rebel group have stalled.

Another round of talks scheduled for December have been postponed as the crisis-hit Thai government handles massive street protests in Bangkok aimed at toppling Prime Minister Yingluck Shinawatra.

National Security Council chief Paradorn Pattanatabut told AFP news agency the culprits may have been linked to the Thai rebellion in the south, and could have been expressing anger that peace talks have faltered while the government concentrates on political turmoil in Bangkok.

"A second theory is it was related to the domestic political situation, to discredit the government," he added.

Thailand's tourist-friendly image as the "Land of Smiles" has been tested in recent years by political violence, devastating floods, deadly bus and boat accidents, and growing concerns about crimes against foreigners.

Source: Agencies