Dhaka: The hunt for the main suspect linked to a fatal bombing that killed 20 people and injured more than 100 in the Thai capital on 17 August has concluded, police announced on Monday, reports Channel News Asia.

The search came to an end with a confession of Bilal Muhammad, also known as Adem Karadag, a foreign male arrested in connection with a weeks-long probe into the deadly blast at Bangkok’s popular Erawan Shrine.

Since the attack, Thai police have interviewed more than 200 witnesses and reviewed footage from security cameras. They have also found at the shrine ball bearings and pieces of a damaged bag believed to have carried the bomb.

As for the second bomb attack that rocked the Sathorn Pier on 18 August, police have interviewed 30 witnesses and reviewed footage captured by CCTV cameras near the explosion scene. Parts of the detonator was also found.

According to Monday’s announcement, previous raids at two apartments in the Minburi district revealed matching detonators and ball bearings.

‘The case is now concluded. Perpetrators are members of a human-smuggling network,’ said police chief Somyot Poompunmuang, who called the two blasts in Bangkok ‘retribution’ for the Thai government’s crackdown on human trafficking.

‘However, we haven’t ruled out the possibility that this group could have been hired by others. More investigation is needed,’ he added.

So far, police have named 17 suspects in connection with the two bomb attacks in August. Two of them are Thai nationals, including a man known as Odd Payungwong or Yongyuth Popkaew. Police said he is also linked to a separate bombing in Nonthaburi District in 2010 and another in Minburi District in 2014. Both were politically motivated they claimed.

Mr Odd’s connection with the past explosions suggested that the August bombings could involve more than one group driven by different motives, Somyot said.

Of the 17 suspects, two have been arrested, including Bilal, who carries a Turkish passport, and Yusufu Mieraili. Both confessed they were involved in the attacks at the Hindu shrine and the pier.

‘The two suspects confessed because of the witnesses and evidence gathered. We did not force them,’ the police chief confirmed, adding police have sufficient evidence to carry out prosecution.