Prawut said the court approved an arrest warrant for Wanna Suansan who rented an apartment room in Min Buri. The court also approved an arrest warrant for the second foreigner who was seen living in the room rented by Wanna.
Police found fertiliser and explosive that could be used to make bombs inside Wanna's rented room, the spokesman added.
Shortly after the August 17 blast that killed 20 people and injured more than 100 others, the court approved an arrest warrant for a foreigner who was seen on CCTVS placing a backpack in the compound of the shrine before the bomb went off.
On Saturday, police arrested a foreigner at an apartment in Bangkok's Nong Chok district. Police refused to say whether the suspect was the alleged bomber wanted in the first arrest warrant.
Prawut said Monday that the arrested suspect was involved with the Ratchaprasong and Sathorn pier bombings but his nationality was still not clear.
The spokesman said police are also seeking warrants for arrest of several more suspects.