The misleading videos which don't show the Brussels attacks

This still from a video shows a bomb explosion at Domodedovo airport in Russia, in 2011, and is not a picture from Zaventem airport as some claimed on social media

As the news broke of explosions in Brussels, images of the deadly chaos quickly began to appear on social media - but at least two widely shared videos were misleading.

Two explosions hit Zaventem airport at about 07:00 GMT, and another struck Maelbeek metro station an hour later. At least 31 people have been killed and many have been seriously injured in the attacks.

One video appearing to capture the moment the airport blast happened was posted online and sent to the BBC. The date on the video claimed the footage was from 22 March, but in reality it was CCTV material from a bomb attack at Domodedovo Airport in Russia in 2011.

So what were the clues?

The video was grainy, black and white, and it didn't show any clear indication that it was filmed at the airport in question.

Then there was the timing. It is highly unusual for CCTV material, normally belonging to airport security, to be released so quickly and by an unofficial source.

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There were no visual clues that would place the footage at Zaventem airport and checks on websites that allow for a reverse internet search of YouTube material - the same can also be done with stills using websites like Google Images or TinEye - uncovered the real source.

But it wasn't just the airport footage that was being posted on social networks. Video of an explosion on a metro system tagged to the #Malbeek tragedy was also appearing and being shared.

Again through careful checks, this black and white footage was found to have come from an attack in Belarus when 15 people were killed in an explosion on the Minsk Metro in 2011. The original timestamp had been removed.

Claims that the video from the Domodedovo Airport attack showed the Brussels explosion were removed from social media shortly after the BBC's checks were carried out.

While the misleading videos, and stills taken from them, were shared hundreds of times, there was also an element of self-policing, with many people online calling out the fakes:

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Blog by Martin Barber

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