Thai police say they are searching for two more suspects in the failed attack against Israeli diplomats.
Bangkok police commissioner Winai Thongson said the two additional suspects may have trained the three Iranian men who are already detained in connection with the case.
Winai said closed-circuit-camera footage showed the two men leaving a house used by the Iranians in Bangkok where explosives detonated on February 14.
The daily newspaper "Bangkok Post" reported that the three arrested Iranians apparently hired female sex workers while staying in the resort of Pattaya before coming to Bangkok.
Iran's government has denied involvement in the Thailand case or in this week's bomb incidents targeting Israeli diplomats in the Indian capital, New Delhi, and the Georgian capital, Tbilisi.
Compiled from agency reports