Residents of Din Daeng area in Bangkok began to evacuate when protesters drove two tanker trucks fueled by NGV (Natural Gas for Vehicles) gas into the compound.
Reporters saw two NGV cylinders on the trucks and the red-shirted protesters shouted that the flat residents there should leave immediately, prompting speculation that the protesters would explode the gas tanks.
Many residents smelt the odor of the gas and began to flee away, TV footage showed.
Din Daeng is a key entrance to Bangkok as well as a major residential area, where the clash between anti-government protesters and the army took place hours ago.