Details from interviews of witnesses or people with knowledge about the pipe bombs near Siam Paragon last Sunday are state secrets and must remain confidential, Metropolitan Police Bureau commissioner Lt-General Sriwara Ransibrahmanakul said yesterday.
Police are obtaining further clues into the bomb attacks while gathering relevant evidence, and expected to secure arrest warrants for more suspected accomplices in the next few days, he said. Warrants have already been issued for the two suspects seen in surveillance camera footage.
There are three groups of suspects in the bomb attacks - masterminds, bomb-makers and the men who planted and detonated the explosives. The officer said identifying and catching the bomb planters or detonators would be most difficult but finding the masterminds would result in all accomplices being caught eventually.
A key meeting to get updates on the latest progress of the investigation is due to be held at 2pm today at the MPB.
Royal Thai Police spokesman Lt-General Prawut Thawornsiri said one of the two suspects seemed to have a bad right leg, judging from his manner when seen walking in the footage from Sunday night. The appearance of this man, not identified by the alias "Dragon", and special character of his potentially bad right leg matched no profile of criminals on police records.
A security source said a number of men likely to have knowledge about past incidents of political violence had been in military custody for extensive questioning. This unknown number of men, reportedly belonging to three groups with political connections, are now in safe houses and being questioned extensively, the source said.
Another source commented that these men belonged to a political group that had been affected politically by the coup and were still active. There were more details such as similarity in the material and assembly techniques used on the pipe bombs last Sunday, and those used in bomb attacks at 10 locations across Bangkok on New Year's Eve in 2006, in response to the coup in September of that year, the source said.
Police have also found the drivers of two tuk-tuks that refused to take both suspects, who hailed them, to get details about destinations the two men wanted to go to.