Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "The Hour will not be established until two great groups fight each other, and the claim (or call) of both will be the same."
Al-Bazzar recorded it from his teacher Abdullah bin Shabib, who is extremely da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الفتن - أعاذنا الله منها / 11982