South Korea said Monday it had started procedures to suspend the medical licenses of 4,900 junior doctors who have resigned and stopped working to protest government medical training reforms, causing healthcare chaos.

The walkout, which started February 20, is over government plans to sharply increase the number of doctors, which it says is essential to combat shortages and serve South Korea's rapidly ageing population. Medics argue the increase will erode service quality.

Nearly 12,000 junior doctors — 93 percent of the trainee workforce — were not in their hospitals at the last count, despite government back-to-work orders and threats of legal action, forcing Seoul to mobilise military medics and millions of dollars in state reserves to ease the situation.

The health ministry on Monday said it had sent administrative notifications — the first step towards suspending medical licences — to thousands of trainee doctors after they defied specific orders telling them to return to their hospitals.

"As of March 8 (notifications) have been sent to more than 4,900 trainee doctors," Chun Byung-wang, director of the health and medical policy division at the health ministry, told reporters.

The government has previously warned striking doctors that they face a three-month suspension of their licences, a punishment it says will delay by at least a year their ability to qualify as specialists.

Chun urged the striking medics to return to their patients.

"The government will take into account the circumstance and protect trainee doctors if they return to work before the administrative measure is complete," he said, indicating that doctors who come back to work now could avoid the punishment.

"The government will not give up dialogue. The door for dialogue is always open ... The government will respect and listen to opinions of the medical community as a companion for the medical reforms," he added.

Military mobilised

The government last week announced new measures to improve pay and conditions for trainee medics, plus a review of the continuous 36-hour work period, which is a major gripe of junior doctors.

The strikes have led to surgery cancellations, long wait times and delayed treatments at major hospitals.

Seoul has denied that there is a full-blown healthcare crisis, but Chun said that military doctors will start working in civilian hospitals from Wednesday this week.

The government is pushing to admit 2,000 more students to medical schools annually from next year to address what it calls one of the lowest doctor-to-population ratios among developed nations.

Doctors say they fear the reform will erode the quality of service and medical education, but proponents accuse medics of trying to safeguard their salaries and social status.

Under South Korean law, doctors are restricted from striking, and the health ministry has asked police to investigate people connected to the work stoppage.

The plan enjoys broad public support, but a new poll by local media found some 34 percent of people believe the warring sides should start negotiating properly.

"Doctors and the government are not in a boxing ring," said an editorial published Monday in the Kyunghyang Shinmun newspaper, urging Seoul and the doctors to resume talks.

"People's patience is wearing thin... The exit from this quagmire must be found through dialogue between the two sides," it added.