Police said two explosions were heard at about 5.40am.
People living near the area called firefighters after they found a Toyota sedan, with the Nonthaburi licence plate Kor Ror (กร) 2200, engulfed in flames. The owner of the car died about one month ago, police said.
After the fire was extinguished, the fire fighters called explosive ordnance disposal (EOD) police as they discovered three gas tanks with explosives inside the car.
Two of the bombs already went off and the EOD officers were able to defuse the third one. if all the three devices went off, they could cause severe damage within a radius of 100 metres, according to police.
There were no injuries.
Investigators suspected that the incident could have been politically motivated as it took place near the Chaeng Watthana protest site of the anti-government People's Democratic Reform Committee (PDRC).