A Thai military court on Tuesday approved an arrest warrant for a suspect believed to be involved in last week's deadly bombing attacks in five provinces, local media reported.
Four people died and 30 others were injured in multiple attacks on Thursday and Friday in popular tourism destinations and at official buildings.
The arrest warrant was issued Tuesday against a suspect for carrying out an explosion with intent to injure or kill, local news station MCOT reported.
No details were given other than that the suspect is a Thai man, MCOT reported.
Police sought the arrest warrant in a military court because bomb attacks fall under the remit of national security, and the incident was not considered a criminal case.
Earlier Tuesday, police said that DNA evidence collected at one of the bomb sites, in Phuket, matched with a person who was involved in a similar attack in southern Thailand in 2004.
"We believe this person will be key in solving last week's bombing," Police General Srivara Ransibrahmanakul said.
The bombings were likely triggered by the political situation in Thailand, police and government officials said.
Thailand sees regular bomb attacks but rarely beyond its most southern areas. Since 2004, an insurgent movement to create an independent state in three southern Muslim-majority provinces has resulted in thousands of deaths and injuries.