The authorities have confirmed that more than 100 wild birds found dead in the Gengahai region of Qinghai province "died of avian flu", sparking fears that the virus could mix with the A(H1N1) outbreak if it spread.

Tests on 121 dead migratory birds in Qinghai on Sunday revealed the carcasses contained the pathogenic bird flu virus, said a statement from the Ministry of Agriculture.

Local authorities have culled nearly 600 poultry in the region, the ministry said.