SHANGHAI?- Two people in China's coastal Fujian province have died of H7N9 avian flu, the state-run Xinhua news agency reported, quoting local health officials.

The province had 15 confirmed cases of the strain so far this year, while Jiangxi and Zhejiang provinces and Shanghai had also reported human cases of H7N9 this winter, Xinhua said.

It did not say when the two died.

The H7N9 virus passes between birds, but there is not enough evidence to prove that it passes between humans, according to the World Health Organisation.

H7N9 first infected three people in China in March 2013. Since then, it has since infected more than 450 people, killing more than 170.