SEOUL (AFP) - Another doctor at a major hospital that has been the epicentre of the Middle East Respiratory Syndrome (Mers) outbreak in Seoul has contracted the deadly virus, the government said on Saturday.

The 25-year-old female doctor at Samsung Medical Centre has become the 185th person infected with the virus in South Korea.

The country's first case was diagnosed on May 20 in the largest outbreak of Mers outside Saudi Arabia, the health ministry said.

The gigantic hospital operated by the powerful Samsung business group now accounts for 90 out of 185 confirmed cases.

With the doctor included, the total number of infected medics at this hospital now stands at 13.

Following four days with no new cases, two nurses at the same hospital were confirmed to be the 183rd and 184th patients on Thursday and Friday, respectively.

Alarmed, health authorities immediately ordered 12 of 15 patients being treated at the hospital to be transferred to other facilities.

The move was seen as another blow to Samsung Medical Centre whose facilities have been shut down, except for those reserved for the 15 Mers patients.

The death toll remains unchanged at 33 with no fatalities reported over the past four days.

Out of the 185 people diagnosed with Mers, 41 remain hospitalised while 11 of them are in critical condition.