Nearly 85 percent of the trip cancellations were made by people from China, Taiwan and Hong Kong, the KTO said.

The increase rate was higher than the 71 percent recorded a day earlier, pointing to the acceleration of foreigners' trip cancellations, according to industry watchers.

The surge in trip cancellations comes amid escalating concern over the disease since South Korea reported the first confirmed case on May 20.

"If the potentially deadly respiratory disease spreads further in South Korea, a considerable number of foreigners are expected to switch their destinations to Japan," a KTO official said.

An industry source said the trip cancellation rate amounts to some 20 percent for the Chinese in the wake of the MERS outbreak here.

In light of that, as many as 100,000 Chinese are estimated to cancel their trips to South Korea for the whole of June as the monthly average of Chinese tourists to Seoul has reached 500,000, the source said.    

Health concerns over MERS are especially high among the Chinese after a South Korean man who tested positive for the virus flew to Hong Kong on May 26 and subsequently went to southern China.

The Chinese are South Korea's biggest tourist group, with the number of travelers from the nation surpassing 6 million for the first time in 2014.

Earlier Sunday, South Korea confirmed 14 fresh cases of the disease, raising the number of patients to 64. More than 1,800 suspects have been isolated or ordered to remain in self-quarantine in South Korea. (Yonhap)