More than 16,000 food businesses in the city have resumed operations, Shanghai's market regulators announced on Sunday.

The 16,451 businesses have been ordered to conduct thorough self-examination and clear expired food and ingredients to ensure food safety, the Shanghai Administration for Market Regulation said.

Officials said they had beefed up inspections over food safety violations particularly targeting acts involving using expired food materials and additives in production, manufacturing and sales of spoiled food products, and fabricating production or expiry dates of food products.