On Saturday, China Daily reported that the authorities of Guangzhou, China warned that about 30 percent of its live poultry markets were contaminated with the H7N9 avian flu virus.
The newspaper said the disease control authority in Guangzhou urged residents to avoid contact with live poultry after tests done in the past week.
The major hub of South China said last month that it would suspend the trade of live and slaughtered poultry for three-day periods through March to prevent the spread of avian flu to humans.
The latest warning reinforces concerns about the spread of the virus as the death toll in China this winter hit 30 last week and its neighbors South Korea and Japan are now affected by the outbreak.
Chinese disease control experts have warned the public to stay alert for H7N9 avian flu, with more than 100 cases of human infections reported over the last 2-1/2 months.
According to the National Health and Family Planning Commission, China already recorded 106 cases of human infections from bird flu in December alone.
The virus is likely to strike in winter and spring, and farmers have in recent years ramped up measures such as cleaning regimes to prevent the disease.
China has confirmed five bird flu outbreaks among poultry this winter, which has led to the culling of more than 175,000 birds.
Many major cities in the world's third-largest producer of broiler chickens and the second-biggest consumer of poultry have also closed some live poultry markets after people and chickens were infected by avian flu strains for the past couple of weeks.
If the spread of bird flu is not prevented, widespread infection can lead to severe health risks and big financial losses. The last major outbreak in China was in 2013, killing 36 people and causing more than $6 billion in losses for the agricultural sector.
