China is now fearing a bird flu outbreak. The second and third case of human infection of H7N9 virus in China this week was confirmed by authorities while other Asian nations try to control the outbreak of the deadly virus.

According to Reuters, a man who traveled in Jiangsu was diagnosed with H7N9 bird flu on Wednesday, Dec. 21, and is currently being treated in Shanghai. Local authorities are now investigating the origin of the virus in Jiangsu province.

On the other hand, a 44-year-man was also diagnosed with H7N9 in Xiamen, a city in the eastern Fujian province on Sunday, Dec. 18. The report came via local state news agency, Xinhua, late Wednesday. The patient is in a stable condition and is currently getting treated.  Meanwhile, the local government ordered to stop the sales of poultry in the district to reduce the risk of more infections.

Previously, an elderly man from Hong Kong was diagnosed with the disease. Shanghai is the most populated city in China with a population count of more than 24 million while Xiamen has about 3.5 million citizens.

The authorities are now taking actions to prevent further outspread. China has banned imports from more than 60 countries including South Korea and Japan. In the past month, South Korea and Japan have ordered the killing of tens of millions of birds to control outbreaks of different strains of bird flu, causing damage to their poultry industry.

The first outbreak of H7N9 bird flu to have infected humans was reported in China in March 2013, which resulted in 46 deaths. In most cases, the virus results in serious respiratory illness such as pneumonia and has a mortality rate of about 30 percent. Bird flu commonly strikes during spring and winter and in the recent years, local farmers have increased cleanliness measures to prevent the disease.