Deputy Police Commissioner General Pol Col Sriwarah Rangsipramkul said a Thai and foreigner have been arrested abroad and the public prosecutors and Foreign Ministry are in process of seeking their extradition.
But Sriwarah refused to elaborate and to identify the two suspects.
The source said the two suspects were Emrash Davutoglu a Turkish man, and his Thai wife, Wanna Suanson.
The two were suspected of providing accommodation to accomplices in the bombing attack.