I searched for images of the iPad Air. Not all the results were as expected. (Screengrab by Hayley Tsukayama)

Some Google users looking for images using the site's picture search Tuesday morning instead found multiple images of a car crash, in front of a sign that says "Stop" in Russian.

Not all Google users reported seeing the strange search results -- my colleague Brian Fung couldn't duplicate it, while I could. But reports of the weird search results have come in from around the world, across a variety of Web browsers and even when using private browsing modes, which lets people surf without having information saved on what sites they've visited. All of this has led people to speculate that Google's image search had been hacked.

Google did not immediately respond to a request for comment.

But  there's also the mystery of the image itself. Dashboard cameras are very popular in Russia,  and so there are plenty of driving videos, traffic footage and images of car crashes to be found. What's not clear is why this particular image is popping up repeatedly. As Jalopnik reported, users on Reddit seemed to trace the image to an article published in November 2012 about a car crash at a Moscow bus stop that killed three people, including the driver.

In the accident, a woman in a foreign car drove onto the sidewalk and hit two people, resulting in the death of all three. According to the report -- from the Ukrainian publication KarpatNews -- there was no trace of alcohol in the driver's blood at the time of the crash. But there's no indication of why this crash would suddenly pop up online three years after it happened.

On its customer support forums, a Google company representative said that the firm was investigating the matter. By early afternoon, many of the image searches seemed to have returned to normal.

Update: In a statement, Google acknowledged the problem but did not offer further details on what caused the glitch, or why that image was repeated. "Oops--speaking of accidents, we've fixed it!" the company said in a statement. "We apologize. The least we could have done was show everyone micropigs instead."