China's food safety watchdog on Tuesday urged three milk producers in Shaanxi Province to recall substandard infant formula milk powder products.China Food and Drug Administration said in a statement on its website that the three companies concerned should stop producing and selling the substandard products, all of which were made from goat milk.

Excessive nitrate was detected in five batches of milk powder products made by Shaanxi Guanshan Dairy Co. Ltd. on Jan. 23 and March 7 this year. Higher-than-standard selenium was found in another two batches of milk powder products produced by Xi'an Guanshan Dairy Co. Ltd. on April 7. and a subsidiary of Shengtang Industry Co. Ltd. on Feb. 3 this year respectively, according to the watchdog.

The China Food and Drug Administration urged its Shaanxi branch to investigate and hand out stern punishment to the companies in accordance with the law.

Shaanxi Guanshan Dairy Co. Ltd. has already issued a notice on its website, announcing that the company will recall the flawed products, halt production and take rectification measures.

A case involving adulterated milk in 2008 harmed thousands of children and resulted in the resignation of then chief of China's quarantine authority.