Eight people have been rescued so far.
Some Chinese TV shows were even delayed so the blurring could take place.
Visitors were annoyed the zoo had advertised tickets on the premise they had lions.
The art is by the same artist who published an image of an Australian soldier holding a knife to the throat of an Afghan child last year.
The Chinese government denies any mistreatment.
Beijing has pushed back against sanctions imposed by the US, EU, Britain and Canada for the alleged atrocities.
"Relations between the two countries have now reached the level of strategic partnership."
The United States will have to reach an understanding with China on a new global order to ensure stability, he says.
Nike and Adidas are the latest caught up in a backlash.