Over 30 students were hospitalized on Friday after being suspected to be sickened by food poisoning at a primary school in northeast China's Heilongjiang Province, three of them still in hospital.

The pupils, all from a local school in this capital city of Heilongjiang, have developed symptoms of stomachache and diarrhea at 3 p.m. on Friday, some of them suffered from nausea and vomiting, according to local sources.

All the children patients had lunch at a same dinning hall in the school.

Last week, food poisoning has killed one girl and sicken another 459 students in Chinese provinces of Heilongjiang, Shaanxi and Hubei.