Security forces are hunting more than 10 suspects in connection with a series of bomb attacks in Bangkok last week, Prime Minister Prayut Chan-o-cha said on Monday.
Six bombs exploded in the capital on Friday as the city's hosted an Asean foreign ministers' meeting, which was also attended by top diplomats from the United States, China, and other world powers.
Authorities now say that six other firebombs also went off on Friday in central Bangkok, including two that caused fires a in shopping malls in a central shopping district popular with tourists.
On Saturday, three more bombs also went off at three ATM machines in southern Pattani province on Saturday, no one was hurt or claimed responsibility for the attack.
"There are more than 10 people involved that need to be arrested, charged, and investigated for the cause [of the attack]," Gen Prayut said.
"We could not say at the moment who is behind the attack but they are heartless and mean with the aim to create chaos for the country at a time when things are proceeding under a democratic government," he said.
Two men have been detained since Friday, accused of planting two bombs, which authorities earlier had said were fake, in front of the police headquarters in central Bangkok a day earlier.
The two suspects from Narathiwat are being held in Yala.
The violence has largely been confined to that region although Muslim militants have been blamed for bomb attacks in the capital in the past.
Reuters could not immediately reach the two suspects or their lawyers for comment. No group has claimed responsibility for the attacks.
No group has claimed responsibility for the attacks.
