Nearly 30 primary school students were poisoned after eating at a school canteen in Haikou, Hainan Province, provincial media reported yesterday.

Police are investigating, as the local disease control and prevention authority reported someone had tainted the food with a poisonous chemical, the Hainan Daily said.

The 26 ailing youths were recovering, it said.

About two hours after lunch on Thursday, the children of the Changmao primary school showed poisoning symptoms like vomiting, stomachache and dizziness.

Nearly 600 students had lunch at the canteen, the report said. The school began its spring term the previous day.

The victims had duck meat, greens, cauliflower and other food. The vegetables came from nearby markets, the report said, without specifying purchase date. Teachers carried the food to the children, it said.

The city Disease Control and Prevention Station took samples of vomited food as well as canteen food and tableware.

Medical workers discovered nitrite, a chemical they said usually is found in vegetables that have been preserved in salt for a few days.

(Shanghai Daily February 18, 2006)