10/26/2012 02:08 EDT | Updated 12/26/2012 05:12 EST

Five kids sick at AGO, taken to hospital; cause of illness remains unknown

TORONTO - The Art Gallery of Ontario says Toronto fire officials have determined air in the building wasn't responsible for making a number of schoolchildren ill this morning.

The AGO says in a statement that paramedics were called after the children became ill at the "Frida & Diego" exhibition space at the Toronto facility.

Paramedics say five children — all between the age of 11 and 12 — complained of flu-like symptoms and were treated and taken to the Hospital for Sick Children.

Fire officials say a hazmat team found nothing out of the ordinary after testing for carbon monoxide, carbon dioxide and oxygen content, so the source of the illness remains a mystery.

After receiving clearance from the fire department, the "Frida & Diego" exhibition space was re-opened.

Toronto police say they are continuing their investigation and focusing on other potential causes outside of the gallery.

(The Canadian Press, CFRB)