JMU said two staff members screened positively over the weekend, while 23 were reported to be infected on July 27. More than 96 individuals who were in close contact with the infected workers were identified and will be checked as well.
The shipbuilder said it had introduced sanitary measures at its facilities, including repeated hand-washing, wearing protective equipment.
After the outbreak the company took steps to clean the facility.
Japan has seen more than 29,000 cases of infection, with 21,000 recovered and 996 deaths.
Maritime Business World