The health ministry served the government's return-to-work order to some trainee doctors taking collective action against a planned increase of medical school admissions quota by a public notice on its official website.

The notice dated Friday says while the order under Act 59 Clause 2 of the Medical Services Act must be delivered in person or via mail to medical personnel who have suspended duties without justification, some could not be delivered due to absence or unverified address.

The notice urged doctors who have received the order to promptly return to work amid concerns that their collective action could lead to massive disruption in public health and lives.

It warned that violators could face legal consequences, including a criminal investigation. 

Those subject to the public notice are 13 trainee doctors affiliated with 12 hospitals, including Seoul National University Hospital, Severance Hospital, and Samsung Medical Center.