Pol Lt-General Sutthipong Wongpin, the acting Immigration Bureau commissioner, led officers who searched six buildings of a condominium complex on Romklao road in Klong Sam Prawet subdistrict of Lat Krabang district at 10am and made the arrests.
Sutthipong said police searched the condominium after two Nigerians were arrested last week on charges of conducting a romance scam in Thailand. Information provided by the two men prompted police to conduct the search.
The immigration officers found 19 Nigerians living at the condominium. Six of them were found to have unlawfully entered the country and five of them had overstayed their visas.
Sutthipong said two other Nigerians were suspected of being involved in the romance scam.
Police also seized 15 passbooks, seven notebooks, 12 phones, one tablet and nine passports from the suspects.