Imam Jafar Sadiq (a.s.) has said that five signs before the re-appearance of Hazrat Qaim (a.s.) would appear:
(i) The appearance of Yemani,
(ii) Revolt of Sufyani,
(iii) Mysterious voice,
(iv) Murder of a pious man between Safah and Marwa,
(v) Sinking of Sufyani's army between Mecca and Medina at a place known as Baiza.
(Behaarul Anwaar, vol. 52, pg. 254)