Counterterrorism officers conducted checks at a refugee reception center in Lavrio, southeast of Athens, on Friday.
The inspection was carried out following the arrest of five Turks earlier in the week in connection to a speedboat carrying arms and explosives from the island of Chios to Turkey. There are currently 170 refugees housed at the center.
Officers took in nine Turks, nine Syrians, nine Afghans, one Iraqi and one Iranian for further questioning.
Reports in Turkey suggested that Prime Minister Recep Tayyip Erdogan had earlier called Greek Premier Antonis Samaras to congratulate him on stopping the boat that was allegedly carrying two members of the militant left-wing Revolutionary People’s Liberation Party-Front (DHKP-C), which is accused of carrying out terrorist attacks in Turkey.
Three Greeks have also been arrested in connection to the speedboat.