SEOUL (AFP) - Some 209 primary schools shut down on Wednesday as South Korea struggled to contain an outbreak of the Middle East Respiratory Syndrome (Mers) virus that has infected 30, killed two and triggered widespread fear.

With the World Health Organisation predicting further infections and the government under fire for its initial response, President Park Geun Hye convened an emergency meeting with top health officials and medical experts to map out a comprehensive quarantine strategy.

Five new cases were reported overnight, making this the largest outbreak outside Saudi Arabia, where the virus has killed more than 400 since 2012.

With new infections being reported on a daily basis, the outbreak has caused nationwide public alarm and seen fearful urban residents stocking up on face masks and hand sanitizers.

Dozens of public events have been cancelled, while more than 1,360 people who were exposed directly or indirectly to the virus have been placed under varying levels of quarantine.

Park has already scolded health officials for their "insufficient" initial response, during which one infected man managed to travel to China despite warnings from doctors.

Mers, which has no known cure or vaccine, is considered a deadlier but less infectious cousin of Severe Acute Respiratory Syndrome (Sars), which killed hundreds of people when it appeared in Asia in 2003.

Education Minister Hwang Woo Yea said 209 primary schools had temporarily shut down, as he urged regional education heads to ensure student safety.

"Infection among students should be prevented at any cost ... we need far stronger measures at schools than anywhere else," Hwang said.

The two deaths reported so far were of a 58-year-old woman and a 71-year-old man.

The first, or "index" case - a 68-year-old man diagnosed after returning from a trip to Saudi Arabia - was reported on May 20.

"Given the number of clinics and hospitals that cared for the index case, further cases can be expected," the WHO said in a statement from Geneva on Tuesday.

The health body said it was closely monitoring the outbreak of what it described as an "emerging disease that remains poorly understood."

Mers has now infected 1,161 people globally, with 436 deaths. More than 20 countries have been affected, with most cases in Saudi Arabia.