particular mosque was targeted? >> reporter: there's a lot of speculation, martin, about why it was targeted. some are suggesting because it was a mosque built by sufis, muslim mystics who are diametrically opposed to the jihadi philosophy of isis. but the fact of the matter is, it's just the mosque by the side of a busy road. at the time of friday prayers, people stop at the nearest mosque. but perhaps that's why they targeted it, because, in fact, isis is opposed to the sufis. they call sufiism a disease, and those who follow it heretics. we know on the 16th of november last year a 100-year-old sufi sheikh was be headed by isis.