Nearly 8,000 South Korean trainee doctors have not reported for work in a protest against a government plan to increase the number of seats at medical schools, which is aimed at reversing a shortage of physicians.

The Ministry of Health and Welfare said Wednesday 7,813 trainee doctors had left their work sites, a sharp increase from the 1,600 a day before when the labor action started. The ministry has ordered 6,112 of the trainee doctors to return to work and said resignation letters submitted by 8,816 of the trainee doctors have not been accepted. Nationwide there are about 13,000 of the doctors, who play key roles in providing emergency care and are similar to medical residents.

So far the labor action appears to have only caused minor disruptions to the heath care system. The Seoul National University Hospital, a major hospital group, said it was functioning normally with some delays in surgeries. The Asan Medical Center said about 60% to 70% of its surgeries were proceeding as planned with staff absences affecting the remainder.