Cases of avian influenza  have been confirmed among wild fowl in western China, Reuters reported, citing its agriculture ministry on Saturday, as concerns grow over a US outbreak infecting cattle herds.

Two counties in Qinghai province confirmed 275 cases of H5 influenza among dead Pallas's gull and other wild birds, China's Ministry of Agriculture and Rural Affairs said in a notice on its website.

The ministry received a report on the cases from the China Animal Disease Control Center, and the national Avian Influenza Reference Laboratory confirmed the finding, the notice said.

The H5N1 outbreak among dairy cattle in at least nine US states since late March has raised questions over whether it could spread to humans. No such cases have been reported.

The US announced on May 11 that it would spend close to $200 million to fight the outbreak.

News of the China cases came as the nation's anti-graft watchdog announced a corruption probe of the agriculture minister on Saturday.