China Death Rat Poison Kindergarten
A doctor examines a child for signs of infection at a kindergarten in Hefei, Anhui provinceReuters

China's food security problems continue to grow after two children died and another 30 fell ill after poisoning at a kindergarten in southwestern China.

Investigators have identified the toxic substance as rat poison, a type that is banned because of its threat to human health but remains in circulation.

The poison is Tetramine, a banned neurotoxic rodenticide, and was found in snacks brought to the kindergarten by a student who shared them with other children, a local government official was quoted as saying.

Two girls, aged four and five, passed away from the poisoning while seven children remain in critical condition. The rest of the ill children have been discharged from hospital.

The Jiajia kindergarten in Yunnan province's rural Qiubei county had been accepting students last year despite not being fully licensed as an educational institution for children, according to state broadcaster CCTV.

It had earlier been claimed that the cause of ingestion by the children was unknown but the food served at the school was tested and found to be safe, a statement by the provincial government said.

The statement also said that it was unclear whether the poisoning was intentional or accidental, despite the local government official's claims.