BANGKOK (THE NATION/ASIA NEWS NETWORK) - It has still not been confirmed whether a suspect arrested in Malaysia is the prime suspect of the fatal Erawan Shrine blast, Thailand's national police chief Somyot Poompanmuang said on Monday (Sept 21).

He also refused to shed light on the progress of investigation into the Aug 17 attack, which killed 20, mostly foreigners, and injured over a 100 others.

Latest reports say that the Malaysian police have arrested a man who looks like the suspect in a yellow T-shirt, who was captured on closed-circuit television leaving a backpack behind that is believed to have been carrying the bomb.

Malaysia has sent a photograph of the man arrested to Thailand for further verification.

Another photo that Malaysia sent was of a "blue-shirt man", also taken into custody in Malaysia, who allegedly kicked a device into the Chao Phraya River in Bangkok, which blew up under Sathorn Pier.

Thai security agencies will check the pictures of the two men to see if they match images captured on surveillance footage.

Thai security officials will also show the pictures of the two suspects to Yusufu Mieraili, who was nabbed last month near the Cambodian border after the blast.

He has admitted to meeting the alleged bomber outside Hua Lamphong train station and handing him a backpack containing the explosives used in the attack.

Thai police said if Mieraili identifies any of the men as a bomber, the police will seek that person's extradition for prosecution in Thailand.

General Somyot said both sides have discussed the issue and the results will be revealed soon.

Police also arrested two suspects allegedly involved in the bombing, and have issued arrest warrants for 12 others.

Assistant National Police chief Prawut Thawornsiri refused to name the blue-shirt bomber, saying more investigation was needed.

The police will also summon the taxi driver who picked up the blue-shirt bomber for questioning, he said.