The two bombing attacks in Bangkok last month were retaliation against the Thai government's suppression of human trafficking gangs, Thai authorities said on September 28.
Other possibilities are not yet ruled out, but currently there is no positive evidence for other motives, said Winthai Suwaree, spokesman of the National Council for Peace and Order (NCPO) at a televised press conference.
Thai police arrested Adem Karadak and Mieraili Yusufu, who were believed to be involved in the blasts at Erawan Shrine on August 17 and the Sathorn Pier on August 18.
The two suspects have confessed their crimes and were taken to reenact the crime at the sites on September 26.
The reenactment of the incidents in relevant areas has proven to be consistent with the evidence and investigation result, said the spokesman.
Adem Karadak and Mieraili Yusufu have been charged with participating in a premeditated murder, in an attempt of premeditated murder, joint unauthorized possession of offensive weapons and joint possession of unauthorized explosives, among others.
Winthai also confirmed that investigators are also working hard to bring other accomplices to justice.
The Erawan Shrine blast killed 20 people and injured more than 120 others, while the Sathon Pier bombing caused no casualties.-VNA