The National Council for Peace and Order said it was for the moment ruling out any link between the Erawan shrine bomb in Bangkok and international terrorism.
In a daily briefing on national television on Thursday, NCPO spokesman Winthai Suvaree said security agencies collaborating with Thailand's allies had come to the same preliminary conclusion -- the incident is unlikely to involve international terrorism, and Chinese tourists were not the direct target because people of other nationalities were also affected.
Col Winthai said the bombing was probably the work of organised crime, or kabuankarn.
A bomb exploded at busy Erawan shrine on Ratchaprasong intersection on Monday night, killing 20 people and injuring another 125. The police investigation has led to the issue of an arrest warrant for an unnamed foreigner, based on CCTV footage, and two more men were being sought for questioning.
A month to plan
National police chief Somyot Pumpunmuang said Thursday morning that the deadly bombing took more than a month to plan and was executed by more than 10 people.
"This blast was made by teams," Pol Gen Somyot said, adding it would have taken about a month to plan Monday's assault on the Erawan shrine.
Stating his belief that "more than 10 people" were involved, Pol Gen Somyot said the bomber would have needed several people to survey the site, plan an entry and exit strategy and acquire and make the bomb, which brought carnage to the capital at rush hour.
"I believe this network has links with people inside Thailand," he added.
Victims' families contacted
The bombing claimed the lives of at least 13 foreigners -- from China, Hong Kong, Indonesia, Malaysia and Singapore. One of the Hong Kong victims was also a British national.
The government has already contacted the families of 16 victims, helping them submit documents for compensation, and nine have already received payment. Of the injured, 70 people have been contacted to submit the necessary papers, and some of them have already been paid.
According to the Public Health Ministry, 56 of the injured have left hospital, while 67 remained hospitalised as of Thursday morning.
Col Winthai said the identities of most of the deceased had been verified. Two were still being verified, so people who think they may be their relatives should contact the Police Hospital.
He warned that the NCPO would increase the level of legal action against people who post misinformation about the bombing on social media, and against people who incite confusion and panic.
AFP news agency reported on Thursday that Prime Minister Prayut Chan-o-Cha said he would not attend a memorial service for the victims at the shrine on Friday because of growing fears for his safety.
"I will not go there on the advice of my security. I am not afraid of dying, but I am afraid others may die with me as my risk is increasing day by day," he said during an official function at Bangkok.
Nobody has claimed responsibility for the attack, which has no precedent in Bangkok.