Shanghai's market regulators have tightened food safety management amid the resurgence of the COVID-19 pandemic as high-risk foods like raw aquatic products have been banned for the supply of group meals.The ban also covers salads and re-processed delicatessen items, according to a notice released by the Shanghai Administration for Market Regulation on Saturday night.Food supplied to groups should be fully cooked to prevent cross infection, and management will be strengthened for the processing, cooking, storage and transportation processes of food supply, the notification states.