SEOUL - A pregnant woman has died of pneumonia related to an unidentified virus, nearly 15 days after the same cause brought about the first fatality in South Korea, local media reported Thursday.

The 36-year-old woman died early Thursday morning, about one month after being admitted to the intensive care unit of a large hospital in Seoul, according to the Korea Center for Disaster Control and Prevention (KCDC), Seoul's Yonhap news agency reported.

She initially showed cold-like symptoms but later was diagnosed with pulmonary fibrosis. The victim was among eight patients who checked into the intensive care unit of the hospital for infection with the unknown virus.

Seven of the eight patients have recently given birth or are expecting, prompting widespread fears among the country's pregnant women.

The KCDC has been focusing on verifying the origin of the virus by studying the specimen taken from the patient and conducting genetic analysis on it.