XI'AN - Milk products that were previously suspected of sickening 251 pupils in Northwest China's Shaanxi province were found to be free of toxins or other potential contaminants, a local government commission said Tuesday.

The food safety commission in the city of Yulin's Yuyang district said that test results have shown that the Mengniu-brand milk drank by the sickened students meets national health and safety standards.

The tests found no pathogens in the milk, nor in the students' vomit and excreta, the commission said in a statement.

Further investigations into the cause of the incident are still under way.

The 251 students of the Yuhe Town Central Primary School fell ill after drinking milk at breakfast on Friday. Sixteen of them showed signs of poisoning, including fever, abdominal pain and diarrhea.

All of the sickened students were discharged from the hospital by Saturday after receiving medical treatment.

The milk was purchased by the district's education bureau and distributed to the students every morning.