Thai authorities arrested the main suspect today in a terrorist attack that killed 20 people and injured more than 100 in Bangkok last month.

Prime Minister Prayuth Chan-ocha said the man was arrested on the Thai-Cambodian border.

“He is foreign, not Thai,” he said.

The suspect was arrested at around 11am (0400 GMT), 500 metres from the Cambodian border.

“We are confident that the arrested suspect was directly involved with (the attack),” police spokesperson Prawut Thavornsiri said.

Police confirmed that the suspect had been flown back to Bangkok by helicopter to be interrogated by the military.

Authorities also issued arrest warrants for three new suspects, all Turkish nationals, for carrying ‘bomb-making substances’.

“The three suspects were residing in an apartment in Minburi (where bomb-making materials were found),” Prawut said.

Security analysts had said the Aug 17 attack did not fit the pattern of local and regional terror groups.

Some commentators speculated that the most likely culprits were Turkish far-right groups unhappy with Thailand’s deportation of Uighur refugees to China. Uighurs are a Turkic minority in north-western China and speak a language related to Turkish.

A different foreign suspect had earlier been arrested Saturday in the Minburi area of Bangkok.

Police found fuses, ball bearings and pipes in the apartment.

Police also found dozens of fake Turkish passports.

Identities of three accomplices revealed

Army Chief Udomdej Sitabutr said the suspect had revealed the identities of three accomplices to investigators.

Authorities later revealed pictures of two suspects, an unidentified Asian man and a Thai woman shown wearing a hijab.

The Thai woman, identified as Wanna Suansan and living in Turkey, has since contacted Thai authorities to declare her innocence, according to the army.

Six Thai immigration police, including a senior officer, were earlier transferred for allegedly taking bribes that allowed one of the bomb suspects into the country.

They were removed from Sa Kaeo, a border province 200 kilometres west of Bangkok and the main overland route between Thailand and Cambodia.

Many of the casualties in the Aug 17 bombing at a popular religious shrine in central Bangkok were ethnic Chinese tourists.

- dpa