A kindergarten teacher in central China's Henan Province is suspected of poisoning at least 23 children, police confirmed on Monday.
The children were vomiting and experienced loss of consciousness on March 27 after their teacher added nitrite, a chemical preservative, in their food.
Among the children, one is in critical condition and 15 others have been discharged from hospital.
The teacher was arrested but her motive was not immediately clear.
An investigation is currently underway.