Nakhon Phanom police chased down a pickup in Muang district early Monday and seized 400 kilograms of marijuana, but the driver got away.
Police signalled the driver to stop at a checkpoint near the Ban Tha Kwai intersection in Tambon Arj Samart, but instead he sped past, heading downtown.
Officers gave chase and caught up on Thai Soi Thani Sopsan Road in Tambon Nong Yart.
The driver abandoned the truck in a rice field and fled on foot.
Ten bags found in the back contained 400 bricks of marijuana, each weighing one kilogram.