Thai authorities have sought Interpol's help in asking Bangladesh to track down the man suspected of masterminding the Bangkok bombings.
"Evidence shows the alleged mastermind went to Bangladesh," deputy national police Commissioner Pol General Jakthip Chaijinda said yesterday.
A source said that Abu Dustar Abdulrahman or Izan, now identified as the chief plotter of two recent blasts in the Thai capital, left Suvarnabhumi Airport for Bangladesh via BG0089 flight on August 16.
The first bomb rocked the Erawan Shrine on August 17, killing 20 people and injuring more than 100 others. The second explosion occurred near the Sathorn Pier the following day without causing any casualties.
"Based on the testimonies of suspects in custody, Izan is believed to have been the big boss in the bombing," Jakthip said yesterday.
Thai authorities have already arrested two suspects in connection with the shocking explosions. They are Mieraili Yusufu and Adem Karadag.
"Their testimonies are useful to the ongoing investigation," Jakthip said in his capacity as the chief investigator in the case. He added that relevant authorities were also looking into some money transactions wired from overseas to determine if they were meant to fund the Bangkok bombings.
Police yesterday took Mieraili to many locations to re-enact his alleged crime, one of the sites being a bank in the Ramkhamhaeng area.
"The Anti-Money Laundering Office [AMLO] is urgently probing related financial transactions in a bid to nail down all culprits involved in the bomb plot," police spokesman and national police Assistant Commissioner Lt-General Prawut Thavornsiri said.
Another police source said recordings from a closed-circuit TV system showed Mieraili and Izan together visiting a bank in Ramkhaemhaeng Soi 22 on August 5.
Mieraili yesterday wore a bulletproof vest during the crime re-enactment, and was seen smiling on several occasions.
"He's not under stress. He also thanked the Thai police for taking good care of him," a source said.
According to the source, Mieraili was given rice with spicy beef and bell pepper cooked by a Muslim-food shop for his lunch yesterday. The suspect was also allowed to keep his prayer rituals in line with his religious beliefs.
Security was tight throughout the crime re-enactment and Mieraili's ride to the Min Buri Court, where police sought permission to detain the suspect for 12 days.
The court approved the police request, and he was sent to Min Buri Prison.
It remains unclear if suspects in the bomb case will face a military court or a civilian criminal court.
"We will have to conclude the investigation before public prosecutors can decide on that," national police Commissioner Pol General Somyot said yesterday.
He added that police did not believe everything the suspects said, as it was also necessary to verify their information with available scientific evidence.
Prawut said Mieraili had told police that the man seen in a blue shirt and kicking a bag believed to have contained a bomb into a canal near the Sathorn Pier was known as Zubair.
"But we will investigate further before we identify this suspect by name," Prawut said.
He also dismissed reports that Mieraili had confessed to having built the bomb.
To date, 11 arrest warrants have been issued for 11 suspects who are believed to have played a role in the Bangkok bombings. Of them, one is a Thai woman by the name of Wanna Suansan.
While Wanna initially communicated via social media that she would surrender, she has not yet come forward.
"We believe some other Thais are also involved," Prawut said.
Defence Minister General Prawit Wongsuwan, who is also the deputy prime minister overseeing security affairs, said Thai authorities would try to nail down all the culprits.
"We expect more arrest warrants. The blasts have caused serious damage to the country," he said.