Person-to Person Transmission Feared

South Korea's health authorities Friday reported two more "probable" cases of swine flu, raising concerns that a person-to-person transmission of the highly contagious disease took place in the country, according to Yonhap News Agency.

The Korea Center for Disease Control and Prevention (KCDC) said in a statement that a female patient in her 40s is suspected of having contracted the influenza without traveling to affected countries. She lived with another woman who was recently reported as the country's first probable swine-flu case Tuesday.

If the two cases are confirmed to be the variant H1N1 type-A influenza, it would mean the country's first person-to-person transfer of swine flu. The first patient, a 51-year-old woman, has been quarantined at a state-designated hospital for treatment and is reportedly recovering.

Others suspected of having been infected with the flu virus have no ties with the first probable patient, the disease control center said.

Patients are identified as "probable" when they test positive for type-A influenza that regularly causes outbreaks among pigs and is transmittable to humans, but negative for human variants of the virus.

It takes up to two weeks to confirm if a person has caught the swine flu, which claimed more than 170 lives in Mexico and one in the United States.

Swine flu is spreading across the globe at a faster-than-expected pace, bringing the number of affected countries to around 30 including Canada, Spain and New Zealand. Japan recently reported a suspected swine flu case.

The World Health Organization (WHO) earlier warned that swine flu is threatening to become a pandemic, raising its swine flu alert level to the second-highest level.

South Korea has also intensified precautionary efforts by restricting travel to Mexico, the epicenter of the outbreak, while tightening quarantines of pork imported from affected countries.

On Tuesday, the disease control center raised its alert level by one notch to "Yellow" from the previous "Blue," a move aimed at intensifying cooperation to stem the outbreak of swine influenza.