GUIYANG -- Three people in southwest China's Guizhou Province have been detained by police for spreading a rumor about the deadly H7N9 bird flu virus online, local authorities said Wednesday.

Two netizens, surnamed Li and Cai, are being detained for five days for spreading false information as no H7N9 cases have been reported in the province, according to the public security bureau of Guiyang, the provincial capital.

They wrote on their microblogs Monday that "sample tests were positive for the H7N9 virus in Jinyang live poultry market in Guiyang." Many netizens reposted the message online, according to the bureau.

Another netizen, surnamed Gong, actively participated in spreading the rumor, which caused fear among some netizens and local people. Gong is being detained for 10 days, according to the bureau.

As of Tuesday afternoon, China had reported a total of 28 H7N9 cases in Shanghai municipality and provinces of Jiangsu, Anhui and Zhejiang, including nine which ended in fatalities, according to the National Health and Family Planning Commission.