While Zawahiri's message exhorted Syrians to "rise above sectarian affiliations", it also appealed directly to those same religious divisions, referring to the "criminal Alawite regime" of Mr Assad, whose faith is an offshoot of Shia Islam. Many fear that if his regime falls, his fellow Alawites will suffer reprisals at the hands of the Sunni Muslim majority, to which most of the rebels belong.