BEIJING - No epidemic link has been detected so far among the H7N9 infections in China, an official of the country's health authority said on Monday.

The authorities have monitored 621 close contacts of the infected patients and to date there is no abnormality among them, said Liang Wannian, director of the H7N9 influenza prevention and control office under the National Health and Family Planning Commission (NHFPC).

As of midnight, the NHFPC has received 21 reports of human infection of the H7N9 avian influenza virus, Liang said at a press conference held by the commission.

According to Liang, ten of the reported cases were found in Shanghai, six in Jiangsu province, two in Anhui province and three in Zhejiang province, Liang said, adding that four patients in Shanghai and two in Zhejiang died of the disease.