A man has died from the H7N9 bird flu strain in eastern China, state media reported Monday, at the end of a year in which cases of the virus have accelerated.

The deceased man was one of two recent cases reported in the city of Yongkang in Zhejiang. They were the third and fourth in the province "since the start of winter", the China News Service reported.

The death emerged as hospitals in Hong Kong were put on alert after a woman diagnosed with the potentially deadly virus was said to be in critical condition.

Health officials in China notified the World Health Organization (WHO) earlier this month of 11 new H7N9 cases on the mainland, including five deaths.

Recent statistics compiled by health authorities in Beijing show 310 cases were diagnosed on the mainland from January until December 10 this year, which include 132 deaths.

Last year the country recorded 46 deaths and 144 cases since the outbreak started in March 2013.

The virus ignited fears that it could mutate to become easily transmissible between people, threatening a global pandemic.

But Chinese officials and the WHO say there is no evidence of sustained human-to-human transmission, despite occasional instances of apparent infection between family members.