Police arrested nearly 500 foreigners during surprise raids in more than 200 locations nationwide. Most of them were illegal immigrants.
Police said they checked official documents of foreigners at 238 spots nationwide, focusing on hotels, entertainment places and linguistic and private schools on Wednesday.
The raids found 478 foreigners had committed wrongdoings. They included 295 illegal immigrants, 24 illegal workers, 26 registered migrant workers who did not stay at designated places and seven visa-overstayers.
The operations were aimed at boosting security ahead of the Asean Summit, police said. The summit officially began on Thursday.
