Nebraska reported on Tuesday an outbreak of highly lethal bird flu in a flock of 570,000 chickens being raised for meat.

Millions of US broiler chickens being raised for meat, egg-laying chickens and turkeys have been infected with bird flu since February or culled to prevent the spread of the disease.

Earlier this month, the US Department of Agriculture reported outbreaks of a highly lethal type of bird flu in commercial flocks in Maryland and South Dakota, adding to concerns that wild birds are spreading the disease across the country.