Pic: AP.

BEIJING (AP) — China’s education ministry has ordered a nationwide investigation into whether schools are giving students medication without permission after a protest by parents of kindergarteners who were given an anti-flu drug.

Tuesday’s announcement came a week after a protest by parents in the city of Xi’an whose children were given the drug. Some children suffered stomach pain and other symptoms but authorities say it is unclear whether it was linked to the drug.

Police in Xi’an said two kindergartens gave children the medication to improve attendance rates and boost their incomes.

A kindergarten in the northeastern city of Jilin also was found to be giving the drug to students.