SIGNS FOR THE IMMINENT APPEARANCE OF THE MAHDI 2
Another set of signs is the appearance of the Sufyani and black banners in the east. He is not a Muslim despite professing being one. He is a mass murderer, but will be swallowed up by the earth in the desert outside Makkah. Shortly thereafter the Dajjal will appear.
Source: AL MAHDI by Muhammad ibn ‘Izzat Muhammad ‘Arif