US poultry producers' shares have taken a dive after reports of bird flu on an Arkansas farm.

According to Reuters , which cited a spokesperson at the US department of agriculture , there is "a suspect case in Arkansas". The spokesperson added testing was ongoing.

Arkansas is home to Tyson Foods . Shares in Tyson fell 5.61% in after-hours trading to US$37.55. Sanderson Farms saw shares fall 4.22% to US$79.03.

In the past week cases of highly pathogenic H5N2 bird flu have been confirmed in Minnesota and Missouri.

No one was available from the USDA, Tyson Foods or Sanderson Farms to comment at time of press.