Three Chinese children have died after drinking milk contaminated with nitrate, the official Xinhua news agency reported on Friday, underscoring continuing problems in the country's food supply chain.

Xinhua said three children died and 35 other people, mostly children under 14, were being treated in hospitals in Gansu province for poisoning after drinking contaminated milk. The news follows a recent government announcement that it was upgrading dairy standards in a bold move that would shut down roughly 45 percent of the country's existing dairy companies. It also follows by only one day the dramatic allegations of Zhao Lianhai, who was imprisoned for organizing parents after his son was poisoned in China's 2008 melamine scandal. In an ongoing Twitter feed and a video posted online, Zhao, released from prison on medical parole, alleged a litany of mistreatment since his arrest.