Overuse of food additives and microbial contamination were the primary food safety problems facing China last year, according to the top food authority.

The two together accounted for more than 64 percent of all food safety problems found in random inspections by the China Food and Drug Administration, Yan Jiangying, spokeswoman for the administration, announced on Monday.

"The overall situation stayed stable compared to the previous year as nearly 97 percent of the food products inspected last year were up to the standard," she said.

About 257,000 samples of food were tested nationwide last year.

Additional food safety concerns included heavy metal contamination and excessive amounts of pesticide residues and veterinary drugs, Yan said.

She attributed these problems to contamination of the soil and water and the overuse of pesticides and animal drugs, particularly antibiotics, in agriculture.

"These will also be the focus of our inspections in 2017," she added.