The first two deaths from the Middle East Respiratory Syndrome (MERS) infection were reported in South Korea on Tuesday as tertiary infections were also identified for the first time, raising fears for an exponential increase in contagion.

A 58-year-old woman, who had passed away Monday for acute incompletion of respiratory organ, was confirmed positive for the MERS Tuesday, according to the Ministry of Health and Welfare.

The woman was hospitalized on May 11 for a severe asthma attack, and had close contact with the patient zero for three days from May 15.

A 71-year-old man, who was tested positive for the MERS on May 28, has also passed away, the ministry said.

The sixth infectee was hospitalized for a fever on May 15, and had close contacts with the patient zero for three days from May 15 at the same hospital ward.

He was initially excluded from the government's management list, but was belatedly put under isolation.

As of Tuesday, the number of South Koreans diagnosed with the viral disease surged to 25 as six more cases were identified.

Among the new cases were two tertiary infections, raising fears over an exponential increase in contagion.

Two males aged 73 and 78 each, who had close contact with the 16th infected male, were tested positive.

The two tertiary infectees shared a room for three days from May 28 at the hospital where the 40-year-old man, who was infected from the first patient, was hospitalized before being confirmed positive for the MERS.

The 16th infectee was initially excluded from the government's isolation list, and was later tested positive for the viral disease after the health authorities resumed an epidemiological survey.

Four other cases were infected directly from the patient zero for three days from May 15. One was a 40-year-old male who was hospitalized at the same ward with the first patient, and three were families of other patients who stayed at the same hospital ward with the first patient.