More than 200 schools in four cities and provinces have decided to temporarily close to prevent Middle East respiratory syndrome (MERS) infection among students, Korea’s top education official said Wednesday.

Meanwhile, the number of confirmed MERS patients in Korea rose to 30 as of Wednesday morning.

The announcement by the Education Ministry came two days after two patients were killed by the deadly virus Monday. A total of 209 schools in four MERS-affected regions – Seoul and Gyeonggi, South Chungcheong and North Chungcheong provinces -- are being shut down. Among them, 183 of them are in Gyeonggi Province.

“We have decided that schools need stronger preventive measures than the general society,” said Education Minister Rep. Hwang Woo-yea. “Until epidemiologic studies are completed, we must do everything we can to protect our children.”

So far, there are no recorded infections among school students, nor cases of transmission in Korea outside of medical facilities.

Among the five newly confirmed patients, four of them are believed to have been infected by the first patient from May 15 to 17, at the same medical facility where more than 20 had already been confirmed as infected by the 68-year-old.

As of Wednesday morning, a total of 24 out of 26 patients who have been infected by the first patient were infected at the same facility where they stayed with him from May 15-17.

Questions are being raised over the particular medical facility’s sanitary conditions, as well as sterilisation. The hospital has been temporarily shut down since earlier this week.

The remaining patient is believed to have been infected by the 16th confirmed patient at a different clinic from May 22-28. The 60-year-old man is the third to be infected by the 16th patient, who visited a total of three hospitals during the outbreak, including the one where he stayed with the first patient.

All of the newly confirmed patients are aged 40 or older. The average age is 58.6. The Health Ministry considers those aged 50 or older and those with chronic lung or kidney diseases as the groups most vulnerable to MERS.