At least five police units have joined forces to try to locate and arrest two more men in connection with the "men in black" attacks at the Khok Wua intersection in 2010.
Ronnarit Soomsri, centre, and four other suspects arrive at the Criminal Court from the Crime Suppression Division on Saturday as police requested the court to keep them in detention for another 12 days. (Post Today photo)
Pol Gen Somyot Phumpanmuang, the deputy national police chief, has assigned the Crime Suppression Division (CSD), the Metropolitan Police Bureau, and Provincial Police Regions 1, 2 and 4 to find the men.
Police identified the suspects as Thanadet Ek-apiwat, 39, of Lak Si district in Bangkok, and Watthanachoke Chinput, 29, of Chon Daen district in Phetchabun. Prasobchok Prommoon, deputy commander of the CSD, refused to disclose their current locations, saying only that all information about the two was in the hands of investigators.
Provincial Police Region 1 is responsible for the central provinces, Region 2 the eastern provinces and Region 4, based in Khon Kaen, covers northern and central parts of the northeastern region.
Pol Col Prasobchok said officers were still compiling evidence to ask the Criminal Court for arrest warrants for more suspects.
"More people were involved in the attacks. Authorities are expanding their investigations to include them," he added.
Five suspects were arrested under the warrants approved by the court on Wednesday. Those already in custody are four men — Kittisak Soomsri, Preecha Yuyen, Ronnarit Suricha and Chamnan Phakeechai — and a woman, Punika Chusri.
But Human Rights Watch said on Tuesday that Mr Kittisak had been arrested without a warrant by soldiers on Sept 5. The Thai E-News website, which supports the red-shirt United Front for Democracy against Dictatorship (UDD), posted a report on Tuesday that he had been taken from the Bureau of Skills Development in Bang Khaen district.
All five have been charged with possessing war weapons and explosive devices in connection with the attacks on April 10, 2010, which killed Gen Romklao Thuvatham, a colonel and deputy chief-of-staff of the 2nd Infantry Division at the time, four other soldiers and 21 civilians. The incident marked a major escalation in the conflict between protesters against the Democrat-led government of the day.
Authorities have not pressed murder charges against the five.
Manager Online said on Thursday that police tracked the alleged attackers from Mr Kittisak. Soldiers remembered him riding in a van passing an army Humvee that night after the attacks took place.
Thai Post quoted Pol Gen Somyot as saying on Thursday that the soldiers remembered his face because he had lowered a window and said: "Why the hell are you here? Why don't you go serve in the South?"
Police and soldiers kept an eye on him and developed the investigations from there until they were certain and asked for the arrest warrants, he said.
The CSD received approval from the court on Saturday to prolong the detention of the five suspects already in custody for further interrogation for another 12 days until Sept 24 after the expiry of the initial 48-hour detention period allowed by law.
The CSD cited the need to continue interrogations, collect more evidence and wait for the reports on their fingerprints for the extension.
They were later sent to the Bangkok Remand Prison.
Only relatives of Mrs Punika sought her release on bail, filing a title deed for a land plot in Lam Luk Ka district of Pathum Thani province worth 1.5 million baht. The court has not decided on the bail request.