The first suspect, identified as Adisorn Seejanphong, 29, was apprehended at his home in Soi Wat Thep Leela (Ramkhamhaeng Soi 39).
Police found in his home stereo equipment stolen from the bus alongside clothes and a motorcycle used by the suspect in the incident, said Pol Gen Jarumporn Suramanee, adviser to the Royal Thai Police Office.
Police also arrested a 15-year-old male and seized from him a stereo system stolen from the bus.
The suspects were among three men caught on film while walking near the torched bus and carrying stereo equipment and a television set believed to have been stolen from the vehicle.
The duo have been charged with arson causing death and theft. The suspects allegedly confessed that they entered the bus and took stereo devices but did not burn the vehicle.
Police are tracking down the third suspect identified by his nickname as Bank who was seen carrying a television in the photo. About a dozen more people are believed to have been involved in the torching.
A double-deck bus with registration plates from Kamphaeng Phet province was set on fire with tyres early in the morning of Dec 1. The charred body of a male, identified later as Suradet Khampaengjai, a 17-year-old student of Bangkapi Technology College, was found on the lower deck near the bus toilet.
Suradet was one of five people killed during the clashes last Saturday night and Sunday morning.
The four other victims were RU student Thaweesak Phokaew, 21, and three red shirts ― Viroj Khemnak, 43, Visanu Phaophu, 26, and off-duty soldier Pvt Thanasit Viengkham, 22.