A bomb has exploded at a busy market in Thailand's Muslim-majority south, killing a soldier. Police say three other troops and three civilians have been taken to hospital with injuries.The remote-controlled device was hidden in a motorcycle parked near the market in Narathiwat province, one of three southern Thai provinces hit by more than two years of violence. While Muslim militants are blamed, it is believed criminals and corrupt officials may be using the insurgency as a cover to settle disputes.