LANZHOU, March 29 -- The principal of a kindergarten in Lanzhou, capital city of northwest China's Gansu Province, has been detained by police for feeding children antiviral drugs without permission, local authorities said on Saturday.

Children at the private Litian Kindergarten were given the prescription drug ribavirin.

Nie Aiqin, the kindergarten principal, admitted that 50 boxes of ribavirin had been bought since October 2013.

Children were given the antiviral drug on two occasions. On each occasion they were given tablets three times a day to allegedly prevent infectious disease.

The pharmaceutical supplier is being investigated for selling drugs to the kindergarten.

More than 280 children who attend the kindergarten have received a health examination. Results are due soon.

Similar cases have been reported this month in the northwestern city of Xi'an, the northeastern city of Jilin and central China's Yichang City.