Educational authorities in Yunnan have launched a widespread investigation into a subsidized school meals project, following a series of suspected food poisoning cases affecting hundreds of students in the province.

The Yunnan education department has set up eight teams to inspect rural schools that since last month have been subsidized by the central government to provide nutritious daily meals for students.

The decision was taken after about one-third of the 1,000 pupils at Dingla Primary School in Zhenxiong county were taken to a hospital suffering stomachache, diarrhea or fever after eating a lunch prepared by the school's canteen on April 9.

"Only 19 students remain in the hospital. They are in stable condition but under observation, as required by their parents," Guo Changgui, deputy head of the county's health bureau, said on Sunday.

One of those hospitalized, Lang Jianquan, told Xinhua News Agency about the meal they were given: "The garden peas were difficult to chew and the summer squash tasted sour. I got a stomachache a while after the lunch."

The meal also included fried pork and tofu, according to Wu Daoshun, who has been dismissed as principal of the primary school following the incident.

But he insisted that the reason most students felt ill was due to group hysteria.

The school canteen was run by a private catering company, which bought all the meal's ingredients, except meat, from Guizhou province, according to a statement by the Yunnan education department posted on its website last weekend.

The company's management was poor, as it kept no receipts or records of its purchases, the statement said.

There was also no refrigerated truck to transport raw food or an air-conditioned room to store food in, and the cooking oil, bean paste and vegetables were left on the ground regardless of the temperature, it added.

The local food and drug administration authority has decided to dismiss and fine the catering company and commandeer their facilities in the school canteen.

Yunnan educational authorities also revealed online that two other schools were suspected of causing food poisoning.

At one of them, Cangping Primary School in Zhenxiong county, 59 pupils were admitted to a hospital "feeling sick" after eating packaged cakes provided by the school. Two students were diagnosed with diarrhea and required medical treatment.

Statistics show that more than 291,000 students in 729 schools in Zhenxiong receive government-subsidized school meals starting from March, as part of the project of the central government to improve nutrition for rural students.

"However, in practice, we have found out that schools in economically disadvantaged areas like our county usually lack the infrastructure and management experience to run such a project," said Chen Xin, a Zhenxiong government public relations official.

Chen urged the central government to allocate more money to help local schools improve their cooking facilities and hire professionals.