On the anniversary of the brutal military crackdown in Beijing's Tiananmen Square in 1989, Microsoft claimed "accidental human error" for its Bing search engine temporarily not showing image results for the search term "tank man."

When users searched for the word "tank man" in various parts of the world, including the United States, no image results were returned on Friday.

The iconic image of an anonymous person with a line of military tanks leaving Beijing's Tiananmen Square following a harsh crackdown on pro-democracy protestors is known as "tank man." Around the world, the photo has become a symbol of defiance.

Microsoft claimed in a statement that the problem was "due to an unintended human error and has been fixed" after being alerted by reporters. Hours later, images of "tank man" photographs were retrieved by the search engine.