The blast occurred on a rural road around 9.10am, overturning the car and injuring Don Sai SAO permanent secretary Temduang Wongsa, 53. She was taken to Mai Kaen Hospital for treatment.
Local officials cleared the scene to ensure safety before launching an investigation. Authorities suspect insurgents were behind the attack, aiming to incite unrest.
Officials also noted a pattern of targeting female officials, referencing a March 17 car bomb in Kapho district that injured a female Volunteer Defence Corps member.