Health Minister Cho Kyoo-hong said Tuesday the government ordered community doctors who joined a one-day walkout to return to work, warning that they would face legal punishment unless they comply with the order.

The order came as about 4 percent of the nation's 36,371 community hospitals, excluding dental and Oriental medicine clinics, have been expected to take a day off in protest of the government's medical reform.

The one-day walkout took place a day after about 55 percent of medical professors at four major hospitals affiliated with Seoul National University began an indefinite walkout, further raising concerns about public health services.

"If the medical vacuum becomes a reality, we plan to carry out on-site investigations and gather evidence to launch administrative actions, including suspending practices in accordance with the medical law," Cho said.

"We also plan to take stern actions against social media posts inciting illegal collective action to refuse medical services under the disguise of voluntary participation," Cho said.

On Monday, medical professors at Seoul National University started walking off their jobs, demanding the government readjust a hike in medical admission quotas and fully withdraw punitive steps against trainee doctors.

Medical professors at other major hospitals, including Asan Medical Center, Samsung Medical Center, Severance Hospital and Seoul St. Mary's Hospital, have also vowed to join the walkout.

Late last month, the government finalized an admissions quota hike of some 1,500 students for medical schools, marking the first such increase in 27 years.

The health ministry reported the Korea Medical Association, the biggest lobby group of community doctors, to the Fair Trade Commission for an investigation as it allegedly incited community doctors to take part in the collective action in violation of the fair trade law.

Under the law, business associations are banned from unfairly interrupting the business activities of their members or restricting competition.

The ministry has also issued an order prohibiting 17 senior members of the KMA, including its leader Lim Hyun-taek, from engaging in or inciting collective action. (Yonhap)