More than 500 schools have canceled classes to prevent the spread of a deadly virus that has killed two South Koreans, the Ministry of Education said Wednesday.

As of 5 p.m., students and teachers have been told not to show up at 544 schools, about 3 percent of some 20,000 schools nationwide, a ministry spokesman said.

The vast majority of the total, or 439 schools, are in Gyeonggi Province, where the first case of Middle East Respiratory Syndrome in South Korea was reported.

The rest are in North and South Chungcheong Provinces, close to Gyeonggi Province, which surrounds Seoul.

In Seoul, six elementary schools and a middle school have decided to shut down until Friday at the request of parents.

Still, none of the students or teachers at these schools have come into contact with a MERS patient.

Earlier Wednesday, Education Minister Hwang Woo-yea called for a thorough effort to prevent the disease from spreading to schools, which he said requires extra vigilance.

He, however, said a mock college entrance exam scheduled for Thursday at all high schools will go ahead as planned.

The education office in Gyeonggi Province said it is in talks with school principals in the area to decide whether to make an exception for schools that have canceled classes.

The move came as health officials confirmed that five more people have been infected with MERS in the country, bringing the tally to 30.

South Korea reported its first case of the viral disease on May 21, when a 68-year-old man who had traveled to the Middle East in April was diagnosed with the illness.

Since then, two people have died from MERS. Both had contracted the virus from the first patient.

A day earlier, the Gyeonggi Provincial Office of Education released a guideline for schools to determine on their own whether they should cancel classes.

The final say has been given to school principals.

The Ministry of Education fell short of forcing all schools to close since health authorities have not yet upgraded the MERS alert level from "watch" to "warning."

MERS is a viral respiratory illness that is fairly new to humans with only some 1,100 confirmed cases reported throughout the world.

There currently is no vaccine or treatment for the disease. (Yonhap)