The arrest took place at Poon-anand apartment in Nongchok district in eastern Bangkok. A large quantity of explosive-making materials were found at the apartment.
Initially, police said the suspect was a Turksih but Police spokesman Pol Lt Gen Prawut Thawornsiri late said the suspect carried a fake Turkish passport.
As a result, police could not yet confirm his nationality yet.
Prawut said the suspect was not the bomber but might belong to the movement as police found bomb making materials in his room, including 0.5-mm ball bearings used in the bombs that exploded at the Erawan Shrine and the Sathorn pier.
The arrest was made after about 100 police and troops surrouned the apartment at at 1:30 pm.
Among things found were 0.5 cm diametre ball bearing similar to those found at the bomb sites at Ratchaprasong Intersection and Sathorn pier. The Ratchaprason attack happened on August 17.
Police and troops surrounded the apartment building on Soi Chuamsamphan 11 for about two hours before making the raid.
Several senior police officers joined the raid, including Metropolitan Police Commissioner Pol Lt Gen Sriwarah Rangsitpramkul and Crime Suppression Division Commander Maj Gen Akkaradej Pimolsri.
The suspect was renting rooms No 412 and 414 on the fourth floor of the apartment, a police source said.
The explosion at the Erawan Shrine on August 17 killed 20 victims, mostly foreign tourists. I also injured more than 100 others.
A man in yellow shirt was seen leaving a backpack under bench in the shrine compound shortly before the bomb went off.
Feeds from security cameras led to facial sketch of a foreigner who appeared like an Arab. A police source said the arrested Turkish looks resemble to the facial sketch of the bomber.
Sriwarah said the suspect rented about three to four rooms and police were checking the rooms.
Sriwarah confirmed that police found some materials in the suspect’s rooms that were similar to those used in the two bombs.
Sriwarah added that the suspect had started renting his room in July.