It is considered as the belief of Shia school of jurisprudence that Imam Mahdi as the last Imam of Shia and likewise as savior of the world (by the intention of Allah) will appear at the time that the world is full of oppression (plenty of oppression). Actually apparently there are relatively a similar belief in some other sects as well (somewhat, not exactly). I also have heard that he is going to appear from Kaaba. But I am not certain regarding this matter. Would you please illustrate where will be the place of his appearance?
(Note: I am looking for an authentic tradition regarding the precise place where he will appear from (Shia view))