A kindergarten teacher in Jiaozuo, Central China's Henan Province, was detained for allegedly poisoning at least 23 toddlers, according to local police in a statement published Monday on the Weibo social media platform.

The children were hospitalized in the morning of March 27 because of vomiting after having eaten porridge at Mengmeng Kindergarten, a privately run facility in Jiaozuo. Some children lost consciousness, according to parents. As of late Monday, one child still remained in critical condition, Jiaozuo police said.

An initial investigation found that a teacher surnamed Wang at Mengmeng Kindergarten is suspected of intentionally adding nitrites — a chemical additive that can harm the liver and kidney — to the children’s food, according to the statement, adding that Wang’s motivation is unclear.

The case is another blow to China’s preschool education sector, which has long been haunted by abuse scandals.

Mengmeng is a small, low-cost kindergarten hosting around 64 pupils, mainly children of migrant workers. The facility has been closed for investigation, police said.

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