South Korea has found a box of imported U.S. beef containing banned parts from an unauthorized U.S. meat packaging facility, which has been the third such incident since quarantine inspections of U.S. beef resumed late last month, the South Korean government said on Wednesday.

Rib bones were found in one box of an 17.8-ton shipment that arrived in South Korea on Aug. 5, said a statement of the state-run National Veterinary Research and Quarantine Service.

The entire shipment from that facility will be returned to the United States, it added.

South Korea banned U.S. beef after a mad cow case was reported late 2003. In January 2006, Seoul lifted the blanket ban, but allows only boneless beef from animals under 30 months old to be imported.