Government officials and members of the public attend a multi-faith religious ceremony on Friday. (Photo by Patipat Janthong)

The government and police are warning members of the public against posting false information about Monday’s deadly blast on social media, accusing netizens of scaremongering.

National police chief Somyot Poompunmuang warned those tempted to post fake or irresponsible comments on social media that they would be breaking laws and could face legal action.

Police have already begun targeting those spreading rumours online, which Pol Gen Somyot said was causing public panic and confusion.

The government has set up a committee to sift through online content and images for those deemed inappropriate on various social media networking sites. The committee — made up of soldiers and police officers — has been conducting routine checks and sending reports to Prime Minister Prayut Chan-o-cha every day.

Speaking during his weekly broadcast to the nation on Friday, Prime Minister Prayut urged the public to think twice before sharing any pictures, comments or information about the explosion on social media.

Gen Prayut warned users not to be exploited by fellow members of the online community, whose aim was to spread malicious rumours.

Instead, he urged social media users to help authorities by watching out for suspicious activity and irregularities and reporting them to police.

“Authorities are cracking down on those who are spreading false information on social media in a way that is against the law and resulting in public confusion and fear,” NCPO spokesman Col Winthai Suvaree said.

Meanwhile, an informed source said authorities have detained a policeman for posting a cryptic comment on his Facebook profile page on Aug 15 — two days before the explosion.

It read: “Soon you guys will hear good news (or maybe bad news I don’t know). The entire country will be shaken. Wait and see.”

The source said Pol Lt Pongsart Nonta, 44, a Samre police investigator, has been taken in for questioning.

Pol Gen Somyot also dismissed a report by The Times journalist Richard Lloyd Parry that stated Thai authorities investigating Monday’s bombing were focusing on a foreign man with a Muslim name, Mohammad Museyin.

The police chief said police did not have that information and he had no idea from where The Times got the name.

Gen Prayut confirmed police have not revealed any names of suspects in the bombing attack and said he was also at a loss to explain how The Times had obtained the information.

Pol Gen Somyot on Friday was forced to defend the work of the Explosive Ordnance Disposal team, which came under fire after a BBC journalist found bomb fragments at the blast site.

He said the team collected evidence from that night until well into the following day.

Two men, one wearing a red T-shirt and the other a white T-shirt, were caught on security cameras standing near the suspected bomber as he put down the backpack containing the bomb.

They have turned themselves over to police investigators, who found they had nothing to do with the attack, Pol Gen Somyot said.

He said an unnamed person had offered to contribute one million baht to the reward currently being offered for any information leading to the arrest of the suspected bomber.

The total amount of the reward has now risen to three million baht.

An undisclosed company also offered to help the police investigation into the shrine blast by providing equipment capable of enhancing the quality of security camera footage.

The camera footage, which shows the suspected bomber as he arrived and left the scene, is grainy in quality, Pol Gen Somyot said.

Police are meanwhile still looking for a woman in a black shirt who appeared in the footage near the alleged bomber. They are unsure of her identity and nationality, as she has yet to come forward to investigators.

“We have yet to exclude any possible motives behind the blast because we still don’t have enough solid evidence to prove which theories are most plausible,” Pol Gen Somyot said.

“There is no information to link the Ratchaprasong intersection and Sathon pier explosions with terrorism,” he said.

Col Winthai agreed no theories about the explosion have been excluded yet, but said less credence was being given to suggestions it was planned by international terror groups.

The investigation has progressed significantly but he could not reveal details for fear it could affect the ongoing investigation.

Gen Prayut said authorities have now identified the “target” of the investigation. He did not elaborate.

Thai authorities have been assigned to make contact with the US embassy, which has offered to assist by sharing facial recognition software and equipment. Gen Prayut said the government is considering taking up the offer.

Yesterday, food and beverages were delivered to staff at the Institute of Forensic Medicine on behalf of HRH Princess Maha Chakri Sirindhorn. Their Majesties have also sent condolence letters to the heads of state of four countries — Malaysia, Indonesia, China and Singapore.

In another development, Gen Prayut apologised to Japanese business people for the blast, which he said no one had anticipated. At a speech at a Bangkok hotel on Friday, he told the room that suspects should be arrested soon.