GENEVA, April 16 (Xinhua) -- A mission is scheduled to arrive in China within the week for a week-long assessment of the H7N9 influenza in the country, the World Health Organization (WHO) said Tuesday.

The WHO spokesperson Glenn Thomas said given that the sources were still unknown, further human infections were expected, reaffirming "at the moment there are no signs of on-going human to human transmission."

The WHO announced China had invited a team of experts, consisting of Chinese experts on epidemiology, laboratory tests and clinical treatment as well as experts and officials from the United States, the European Union, Australia and the WHO to carry out a one-week joint assessment of the situation of this deadly disease in the country.

The team will go to the infected areas to assess the outbreak and transmission mode of the influenza, investigate technical characteristics of the virus itself such as source, reservoir and pathogenicity, and guide further prevention and control measures.

The WHO will look into the results in detail to support China to respond to the avian influenza emergency, Thomas told Xinhua.

Silvano Sofia, spokesman of Food and Agriculture Organization of the United Nations (FAO), told reporters that the FAO was working closely with Chinese authorities to develop a market chain analysis to trace the sources of infected poultry back to the farms of origin to identify other infected farms.

She added that in light of recent events, the FAO was reevaluating surveillance protocols in domestic and wild animals.

Sofia commended the Chinese authorities' decisions to release virus information to the public and their agreement to share the virus information with the international community.

"The virus sequence released has allowed scientific communities to perform further analysis and to be better prepared for diagnosis and production of human vaccines," she said.