China’s food safety problems are continuing to dominate headlines. Amid new claims of cadmium-tainted rice in Guangzhou, reports from northwestern Qinghai province are saying that over 500 students have fallen ill after consuming biscuits and milk provided by their school.

Coming off the heels of the newest rice scandal, the reports of rat and fox meat being sold as lamb prior to that, and the other items on China’s long list of food safety scandals, young students have become sick over government-funded school “nutritious” meals.

According to a report by state-owned China Daily, a total of 548 primary and middle school students across seven different townships fell ill on Wednesday from food poisoning after eating contaminated food. The report cited Datong County’s publicity bureau saying that about a dozen of them were in serious condition as a result of the food poisoning.

The meal, which is served between breakfast and lunch, served as a supplementary snack to hold students over. Soon after consumption, students began exhibiting symptoms like vomiting, dizziness and headaches.  A student only identified by their last name, Ma, said that the milk that students were given had “a strange smell.” She drank it anyway and quickly felt nauseous and then fainted in the classroom.

After investigations, it was determined that either the milk or the biscuits were the cause. A local official said that the tainted food could have affected as many as 56 or the county’s 72 primary and middle schools. The local food-safety bureau has confiscated all other foods that also could be contaminated, while some samples have been collected for testing by health authorities.

The free meals began last spring as a government effort to provide the rural students improved nutrition at school.