BANGKOK (THE NATION/ASIA NEWS NETWORK) - The Malaysian police have sent their Thai counterparts photos of two men, one of them believed to be the yellow-shirt bomber involved in last month's Erawan Shrine blast, according to a Thai security official.

The other photo was of a "blue-shirt man" who allegedly kicked a device into the Chao Phraya River that blew up under Sathorn Pier.

Thai security agencies will check the pictures of the two men detained by Malaysia's Special Branch Police in Kuala Lumpur to see if they match images captured on surveillance footage.

Malaysian police on Saturday (Sept 19) searched several apartments and rental rooms believed to be hiding places of the two bombers at the request of Thai police.

A Pakistani and two Malaysians suspected of being part of a human trafficking operation are already being interrogated by the Malaysian police in connection with the shrine attack.

The Malaysian police said the human trafficking gang sheltered the yellow- and blue-shirt bombers at a location 2km away from the Moo Noh police station.

The two were allegedly taken by boat across the Kolok River near Soi Rong Leuy, where two Malaysian men identified as A-pi and Padeh, were waiting on the other side at Bukit Bintang to receive them.

Another Malaysian man identified as Serlin allegedly took the two to Kuala Lumpur.

Malaysian Special Branch Police were tipped off by an unidentified group after a man calling himself Abdul (last name withheld) telephoned the Thai Embassy in Kuala Lumpur, threatening violence against it.

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

He admitted 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.

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

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

In the blast near the Erawan shrine on Aug 17, 20 people were killed including several Malaysians.