BEIJING - Chinese health authorities said on Saturday that the country's 16 confirmed H7N9 cases were isolated and there has been no sign of human-to-human transmission.

As of 5 pm Friday, 16 people had been confirmed as being infected by H7N9 bird flu, six of whom have died, said the National Health and Family Planning Commission in a brief statement posted online.

Six cases, including four deaths, were reported in Shanghai, and three cases, including two deaths, were reported in East China's Zhejiang province.

Elsewhere, Jiangsu province reported six cases and Anhui province one case.

The statement said no epidemiological link between those cases has been identified to date.

All close contacts have been placed under medical observation, and only one of them has shown symptoms, though bird flu infection has already been ruled out as the cause of this person's illness, it added.