CNN is reporting that this is possibly a photo of the assailants.
— Unpredictable man (@raralirana) June 4, 2017
They look like they might be wearing suicide vests. This is all unsubstantiated at this point.
The guy does match the description from an eyewitness given to the media. The photographer says he saw three men.
Here’s an interview with the photographer about how he got the picture:
— BBC News (UK) (@BBCNews) June 4, 2017
Read how the attack report developed on social media here.