Malaysia police said three suspects have been arrested on Monday in connection with the investigation into the Bangkok blast last month which killed 20 people.
Police chief Khalid Abu Bakar said two Malaysians and a Pakistani national were arrested.
"We believe the suspects can help in the investigation... our arrest was made to assist the Thai police in the Thai bombing investigation," said Bakar.
"Malaysian and Thai police are working closely in cooperation."
The arrests came two days after the Malaysian police arrested another two suspects on Saturday, after Thai Police Inspector General Suchart Teerasawat travelled to Malaysia to coordinate an investigation to track down a yellow t-shirted suspect caught on CCTV placing a bag containing a bomb at Erawan Shrine in Bangkok on Aug. 17.
No groups claimed the responsibility for the Bangkok blast on August 17 at Erawan Shrine, which killed 20 people, including 14 foreign tourists.
Thai police believe that international militants are responsible for the attack. Thai National police spokesman Prawut Thawornsiri said it may be a revenge act of a people smuggling network who lost money after a recent crackdown after the discovery of over 30 corpses of Rohingya in jungle camps.
However, Thai police have been criticised in the media over their efforts in the investigation and over often speculative and contradictory statements made by top officials about possible perpetrators of the attack, motives, and information extracted from suspects.
Malaysian police chief Khalid said the Pakistani suspect is a male while one of the local suspects is female and the other one is male, adding there is no plan to extradite them to Thailand yet.