The number of people who have died in China from a lesser known strain of bird flu, H7N9, climbed to five on Thursday, Xinhua news agency reported, citing Shanghai authorities, RIA Nosvosti said.

So far, all the cases of H7N9 avian influenza, which have now climbed to 11, have been registered among people from provinces in east China and the Shanghai Municipality.

The Chinese Ministry of Agriculture said traces of the new strain of bird flu had been detected in pigeon samples collected at a marketplace in Shanghai. The national avian flu reference laboratory concluded that the strain of H7N9 virus found in the samples was almost identical to the strain found in infected people.

Chinese health authorities have already contacted the World Health Organization (WHO), promising transparency and cooperation with the organization over cases of the new strain of bird flu.

On Wednesday, April 3, the Chinese Center for Disease Control and Prevention said there had been no cases of human-to-human transmission of H7N9.