No one was killed or injured in the 9.30am explosion at the warehouse located at the strategic training centre of the forward command of the Royal Thai Police, which is located in Ban Bukekla village.
The explosion ignited a fire that burned down the warehouse.
Troops and police from the Muang Yala police station cordoned off the area and evacuated nearby villagers.
Police said the warehouse was used to keep seized explosives for evidence related to violent cases in the restive deep south from 2018 to 2023. They included ammonia nitrate, ammunition and firecrackers.
Provincial Police Bureau 9 commissioner Pol Lt-General Piyawat Chalermsri said the explosives kept there were used as evidence for cases involving violence. After the cases are completed, the explosives would be disposed of.
He said the explosion had nothing to do with the deep south insurgency and was apparently an accident.