NANJING -- Live poultry trade has been suspended in Suzhou city in eastern China over bird flu concerns.

The ban is effective starting Monday, according to a notice on the website of the Suzhou government.

During the ban, market regulators will disinfect the poultry trading areas, the notice said.

Sources with the city health department said the ban could last a few days or a month. Live poultry bans are usually adopted when a local government decides there is high bird flu risk.

The Suzhou government ordered health authorities to closely monitor the H7N9 avian flu strain. Live poultry markets are a major source of the virus.

H7N9 is a bird flu strain first reported to have infected humans in March 2013 in China. It is most likely to strike in winter and spring.

There have been sporadic reports of the virus since winter began. Two deaths were reported in eastern China's Anhui province.

In November, an 81-year-old patient was infected with the flu in the southern province of Guangdong.

Last week, two more infections were reported in Xiamen and Shanghai. A 44-year-old man was diagnosed with the flu in Siming district of Xiamen city in East China's Fujian province.

The Siming district government halted poultry sales for a day to reduce the risk of infection.

The Shanghai patient was a 45-year-old man who had traveled from Nantong city, Jiangsu province.