The rest must have been Amish.
A funny use of the word “several”, which means “more than 2”.
There were only 4 men. If “several” were muslims, that means either 3 or 4 were muslims. My guess is they knew for a fact that 3 were muslims, but weren’t positive about the 4th. (That’s if they were simply trying to be accurate, although then they should have said 3 were confirmed muslims).
Or, they know all 4 are, and used “several” to suggest, without actually lying, that some were NOT muslim.
Or maybe they know that the 4th isn’t muslim, but I would be if that were the case they would have said so in the 1st sentence of the article.