The man arrested in connection with the deadly bomb blast in Bangkok is not cooperating with police, according to Thai authorities who have also announced that he is part of a people-smuggling gang.

The 28-year-old man, who has been in Thailand since January 2014, was detained on charges of possessing illegal explosives.

Investigators said the man was found with bomb-making equipment and multiple passports during a raid at a flat in Bangkok’s eastern suburbs on Saturday morning.

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Police have not revealed the man’s identity or nationality, however an Internal Security Operations Command (ISOC) spokesman said the man is a Turkish national.

Police have arrested a 28-year-old foreigner over the shrine bombing which left 20 people killed and scores injured. Photo: AFP/Royal Thai Police

“The interrogation is not making progress because the suspect is not really giving useful information,” Thai army chief General Udomdej Sitabutr said.

“We have to conduct further interrogations and make him better understand so he will be more cooperative – while we have to be careful not to violate the suspect’s rights.”

The August 17 bomb at Bangkok’s Erawan Shrine, where Thais and Asian tourists flock each day, stunned Thailand.

Fourteen foreigners, seven from mainland China and Hong Kong, were among the 20 killed in an attack the ruling junta said was intended to cripple an already flagging economy.

National police spokesman Prawut Thavornsiri said on Sunday the suspect was part of a people-smuggling gang who helped illegal migrants obtain counterfeit documents, and the bomb attack was in response to a recent crackdown by Thai authorities.

“They [the gang] are unsatisfied with police arresting illegal entrants,” he told Channel 3 in a telephone interview.

“He [the suspect] had more than 200 fake passports [when he was arrested]. It’s a network that fakes nationalities and sends them [illegal migrants] on to third countries,” he added, without elaborating how he received that information.

Suicide vest broadcast sparks criticism

Police have been criticised for an erratic investigation that had, until this weekend, uncovered few clues about who was behind the blast.

CCTV images of a person suspected to be behind the Bangkok bombing.

No group has claimed responsibility.

In the latest blunder, Thailand’s junta mistakenly showed an unrelated picture of a suicide vest during a nationally televised broadcast announcing the foreigner’s arrest.

The picture of the vest was widely shared on social media, but late on Saturday police took to Twitter to say the photo of the vest was not from the flat.

“The picture has nothing to do with the bombing. It is not official,” police wrote on their Twitter account @PoliceSpokesmen.

“We would like to ask people who published that picture to stop their actions because it might bring concern to society and it could be in breach of computer legislation,” they added in another tweet.

National police spokesman Prawut Thavornsiri, who was the police official in the national broadcast, also tweeted: “The picture that you are putting in your messages might damage the country so please could you stop because the country has already been very bruised.”

Police searching for more suspects

Deputy national police chief Chaktip Chaijinda told Thai television more suspects were being sought.

Police and residents in Bangkok’s Nong Chok district said the suspect rented four apartments on the same floor of the rundown building.

A man and woman living on the same floor said the suspect did not live alone, adding that they had seen a taller man with similar appearance entering and leaving several times each day.

Erawan Shrine, in central of Bangkok, in the aftermath of the blast. Photo: AAP

They had not seen the second man since Friday.

“We’ve seen two of them, frequently. One was the arrested man, but there’s another, he’s much taller,” said the man, who requested anonymity because he feared for his safety.

The detained man was reclusive but always appeared focused and walked with intent on his rare forays outside.

They said he was often seen on his knees praying outside the room.

“I still fear danger,” the woman said.

“We don’t know if the other man has been arrested.”

Speculation has focused on which groups could have motive and capability to carry out the bombing.

These have included southern ethnic Malay insurgents, opponents of the military government, foreign militant groups and sympathisers of Uighur Muslims.

Thailand forcibly repatriated more than 100 Uighurs to China last month, prompting international outrage.

Many of the minority Uighurs from China’s far west have sought passage to Turkey via South-East Asia.

On Saturday, police indicated the person arrested was the prime suspect, a young man with shaggy dark hair who wore a yellow shirt and was picked out on security cameras dropping off a backpack at the shrine and leaving before the bomb went off.

– with agencies