The ministry recorded five deaths yesterday alone, bringing to 16 the number since February 11.
That figure compares with a single death from the virus in the first 10 days of the month.
Saudi Arabia is the country which has been hardest hit by the MERS virus, which was first identified in 2012. A total of 899 people have been infected in the kingdom, of whom 382 have died.
Doctor Abdul Aziz bin Saeed, who heads the centre coordinating the ministry's response to MERS, warned earlier this month that a surge in cases typically occurs around this time of year, because of the risks posed by newborn camels.
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Saeed said "you have more infected camels right now circulating."
The ministry reported new cases from across the kingdom. Half of those who died were in their 70s or 80s.
A public awareness campaign is continuing. The WHO urged people working with camels to pay particular attention to personal hygiene.
Experts from WHO, the Food and Agriculture Organization and other UN agencies are concluding a mission to Saudi Arabia after "a surge in cases in the past few weeks," WHO spokesman Tarik Jasarevic said.
More than 20 countries have been affected by MERS but most cases have been linked to the Middle East.