The government revoked a construction firm's permit to accept foreign technical trainees on Friday after a Vietnamese man suffered serious injuries as a result of repeated assaults by Japanese coworkers over a two-year period.

The firm called Six Create in Okayama Prefecture in western Japan is prohibited from accepting technical trainees for the next five years under the administrative punishment issued by the Immigration Services Agency and the labor ministry.

"Acts of human rights violation against technical trainees must never take place," Justice Minister Yoshihisa Furukawa said at a news conference in Tokyo, adding the government will take strict action if similar cases occur in the future.