Four Vietnamese illegal migrants were arrested by officers in Chiayi, Taiwan, during the early hours of Tuesday.

After months of investigations and surveillance, officers from the Coast Guard Administration as well as from the National Immigration Agency raided a location in Nantou District on March 12, where three women and a man, all from Vietnam, were arrested under suspicion of working illegally, the United Daily News reported.

According to the Chiayi’s Coast Patrol Corps, the Vietnamese man, who was of powerful build, disobeyed the officers’ instructions and tried to escape. He was eventually subdued by an officer who had previously served in the marine corps.

The four arrestees were found to have become illegal migrant workers earning between NT$800 and NT$1000 (US$26 to $32.50) a day after they had run away from their former employment as caregivers or technicians. One of them violated their terms of stay by over a year.

They were referred to the National Immigration Agency for violating the Employment Services Acts. Meanwhile the authorities continued their investigations to track down the employers who were responsible for hiring the illegal migrants.