It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: The people of the tribe of Mudar will continue to kill the servants of Allah until no one remains to worship Allah, or the Muslims will continue to kill them until they cannot prevent them from even the bottom of a vessel.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 11821
Hadith Gradingحکم دارالسلام:حديث حسن، وهذا إسناد ضعيف لضعف مجالد بن سعيد