A tiger on display during the Greater Los Angeles Zoo Association's 39th annual Beastly Ball at the Los Angeles Zoo on June 20, 2009 in Los Angeles, California. (Frederick M. Brown/Getty Images)
The Calgary Zoo said the two men snuck into the facility after midnight and headed to the Siberian tiger enclosure, where one of the men climbed over an outer fence.
"He did not enter the exhibit, but did come into contact with one of the tigers and sustained significant injuries to his arms," the zoo said in a statement.
Alerted to the situation, security guards took the alleged intruders to their office, where the injured man was treated before being rushed to hospital.
Police are investigating.
