Seoul. South Korea's government gave striking young doctors four days to report back to work, saying Monday that they won't be punished if they return by the deadline but will face indictments and suspensions of medical licenses if they don't.

About 9,000 medical interns and residents have stayed off the job since early last week to protest a government plan to increase medical school admissions by about 65 percent. The walkouts have severely hurt the operations of their hospitals, with numerous cancellations of surgeries and other treatments.

Government officials say adding more doctors is necessary to deal with South Korea’s rapidly aging population. The country's current doctor-to-patient ratio is among the lowest in the developed world.

The strikers say universities can’t handle so many new students and argue the plan would not resolve a chronic shortage of doctors in some key but low-paying areas like pediatrics and emergency departments.

Vice Health Minister Park Min-soo said during a televised briefing Monday that the government won’t seek any disciplinary action against striking doctors if they return to work by Thursday.

“We want them to return to work by the end of this month, Feb. 29. If they return to the hospitals they had left by then, we won’t hold them responsible” for any damages caused by their walkouts, Park said.

But he said those who don't meet the deadline will be punished with a minimum three-month suspension of their medical licenses and face further legal steps such as investigations and possible indictments.

Under South Korea’s medical law, the government can issue back-to-work orders to doctors and other medical personnel when it sees grave risks to public health. Refusing to abide by such an order can bring up to three years in prison or 30 million won ($22,480) in fines, along with revocation of medical licenses.

There are about 13,000 medical interns and residents in South Korea, most of them working and training at 100 hospitals. They typically assist senior doctors during surgeries and deal with inpatients. They represent about 30-40 percent of total doctors at some major hospitals.

The Korea Medical Association, which represents about 140,000 doctors in South Korea, has said it supports the striking doctors, but hasn't determined whether to join the trainee doctors' walkouts. Senior doctors have held a series of rallies voicing opposition to the government's plan.

Earlier this month, the government announced universities would admit 2,000 more medical students starting next year, from the current 3,058. The government says it aims to add up to 10,000 doctors by 2035.

A public survey said about 80 percent of South Koreans back the government plan. Critics suspect doctors, one of the best-paid professions in South Korea, oppose the recruitment plan because they worry they would face greater competition and lower income.

Striking doctors have said they worry doctors faced with increased competition would engage in overtreatment, burdening public medical expenses.