Passengers wearing masks to prevent contracting Middle East Respiratory Syndrome (MERS) walk past a thermal imaging camera at Incheon International Airport in Incheon, South Korea, June 1, 2015. [Photo/Agencies]

SEOUL - South Korea on Tuesday reported the first two deaths from an outbreak of Middle East Respiratory Syndrome (MERS) that has affected 25 people in two weeks.

A 58-year-old woman who had had contact with South Korea's first patient died of acute respiratory failure on Monday, the Health Ministry said. A 71-year-old man who had been on respiratory support with a history of kidney ailments also died.

The ministry reported new confirmed cases on Tuesday, bringing the total to 25. South Korea now has the third highest number of cases after Saudi Arabia and United Arab Emirates, according to the European Centre for Disease Prevention and Control.

China reported its first MERS case in a South Korean man who tested positive after breaking a voluntary house quarantine last week, flying to Hong Kong and then travelling to mainland China.

South Korean authorities were considering a ban on overseas travel for the nearly 700 people isolated for possible infection.

The World Health Organization (WHO) said last week there had been no sustained human-to-human spread in South Korea, and that it was not recommending screening of passengers or the imposition of travel or trade restrictions.