A 22-year-old pregnant woman died from a bird flu infection in central China's Hubei Province early Thursday, the Ministry of Health (MOH) said in a website report Friday.

The woman, surnamed Chen, was four months pregnant when she began to show symptoms and was hospitalized in Hubei's Ezhou city on May 23 after the symptoms became aggravated, the report said. However, the statement did not describe the woman's symptoms.

Chen died at 12:35 a.m. Thursday, hours after she tested positive for the H5N1 strain of avian influenza by local disease prevention authorities.

Further, those who had been in close contact with Chen are under medical observation, but none have become ill, the ministry said.

According to the MOH report, Chen had contact with sickened birds before she became sick. Additionally, experts sent by China's Ministry of Agriculture have not found signs of an epidemic of avian flu among birds in the region.

The Health Ministry said it has reported the case to the World Health Organization (WHO) as well as informed health authorities in China's Hong Kong and Macao special administrative regions.