CHANGSHA, Dec. 20-- Nineteen primary school pupils in central China were hospitalized after drinking yoghurt allegedly poisoned by a woman who delivered to them on Wednesday, local authorities said Friday.

Police in Loudi City, Hunan Province, has detained the woman, 34, and suspect that she suffers from mental disorder.

Police said the woman had confessed to having injected rat poison and herbicide into the yoghurt and then delivered the drinks outside a local primary school to students on their way home.

Among the 19 stricken students, three are in a serious condition but doctors said they lives are not in danger.

Further investigation is ongoing, police said.