One very interesting point I noted.
The article says that Christopher Swift, Georgetown University, who specializes on the Chechen War, doesn’t think they were working for Chechen terrorists, because they have NEVER attacked anyone but Russians.
That ties in with the probability that they were connected in some way to al Qaeda and the Saudis, maybe directly, maybe more informally. Or to put it another way, it was their Islamic ideology that motivated them, not their Chechen nationality.
At the least, they attended mosques and associated with other Muslims in the area.
makes sense.