The 28-year-old was in possession of a Turkish passport, however Thai police said: "The passport you see is fake. We don't know if he is Turkish or not."
He is now being detained at a military facility on initial charges of possessing illegal explosives.
Police chief Somyot Poompanmoung said: "It's unlikely to be terrorism. It's not an international terrorist act."
Thai police released an image of Adem Karadag alongside suspected bomb-making material which they say they found in his flat
(Thai police handout)
He said that authorities believe the man's motive was "taking personal revenge for his comrades." He did not elaborate as to who "his comrades" might be or whether they believe his actions to be linked to a wider group.
So far, no groups or individuals have claimed responsibility for the attack.
The blast happened inside the Erawan Shrine in Bangkok's Pathum Wan District and injured 125 people.
Bangkok Bombing
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Thai police say that the arrest took place today after they raided an apartment which they believe was being used by the suspect in northern Bangkok. They say that they discovered suspected bomb-making materials inside the property.
Thai police remove evidence from the apartment
(Reuters)
The police chief told reporters: "The bomb materials are the same, similar, or the same type" as those used in the bombings at the shrine.
Police had previously said they were looking for a man who appeared on CCTV footage of the incident as part of their investigation.
Footage (see below) appeared to show a man in shorts and a yellow T-shirt removing a backpack and placing it underneath a bench inside the shrine, before leaving the area. The bomb reportedly then exploded in the place where the backpack had been left.
More to follow
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