At least 15 people detained for suspected involvement in last week's bombings and arson in seven provinces will be taken to the police Crime Suppression Division and charged on Friday, the National Council for Peace and Order said.
Col Burin Thongpraphai, the NCPO legal chief-of-staff, said the military had earlier arrested and detained 17 suspects at the 11th Military Circle in Bangkok. Two had been freed.
Arrest warrants were now being sought in the military court for all 17 suspects. The two released earlier would be tracked down, he said.
Arrest warrants would ensure they could be held for a longer period pending further investigation.
Col Burin said he passed on more information about the bombings to the Crime Suppression Division (CSD) in Bangkok on Thursday.
Last Thursday and Friday, bomb and arsonist attacks struck six southern provinces - Krabi, Nakhon Si Thammarat, Phangnga, Phuket, Surat Thani and Trang - and bombs also exploded in the nearby central province of Prachuap Khiri Khan, south of Bangkok.
All are major tourist destinations. The attacks were launched at the start of a long holiday weekend in honour of Her Majesty the Queen's birthday.
Four people were killed and 35 others injured, including foreign tourists.
