Now I'm not sure but Muslims have a habit of praying on the street. The van may have been driving along and it was an unfortunate accident and inadvertently hit worshippers. If anything it may be a council issue for not displaying signs against praying in the street or even the Mosque for not advising patrons to pray inside.
Let's get more facts before we blame anyone.
Who would expect to see or even recognise hunched up worshippers like these, especially at night