A bomb allegedly planted in a truck by insurgents exploded at a garbage depot in restive southern Thailand.

The explosive detonated near the Rueso subdistrict government office in Narathiwat province, at 12:30 pm on February 6.

The ensuing flames engulfed a six-wheeler Mitsubishi orange boom truck and four other vehicles in the garage.

Firefighters arrived in three fire trucks and extinguished the blaze in 20 minutes. There were no injuries or deaths reported.

Police said they found fragments of an improvised explosive device that the suspects had assembled and placed in a 5kg metal box. The bomb was said to have been detonated remotely.

Police Captain Khomsan Teekhakan of the local police station said: 'The engineering department took the truck to be repaired at a garage in Rueso Subdistrict Municipality.

'When the mechanics were finished repairing it, they drove it to the parking building, where the bomb exploded at around noon.'

Officers were questioning the mechanics and collecting CCTV footage to determine possible suspects.

Authorities believe the blast was planned by alleged terrorists sowing fear in the region. The explosion occurred hours after a new mayor, Amir Sarikhan, was sworn into office.

The previous mayor, Wichet Thaithongnum, had been gunned down in a horror shooting where four armed men broke into his factory and peppered him with bullets.

Islamic separatist terror attacks target the three southernmost provinces of Thailand - Yala, Pattani and Narathiwat - next to the border with Mulsim neighbors Malaysia. Thai state employees and infrastructure are often hit while attacks on civilians are rare.

Officials believe the conflict dates to a deal in 1909 that the British Empire struck to incorporate the Muslim region into the Siamese mainland.

The region's culture is more similar to Malaysia and dramatically different to Buddhist Thais causing decades of tension that lead to the emergence of separatist groups fighting for independence in the 1960s.

The struggle has continued ever since with more than 7,344 people killed and 13,641 injured between January 2004 and March 2022.

The British Foreign & Commonwealth Office warns against all but essential travel to the region while Canada's government warns its nationals to 'avoid all travel' to the three provinces.