In The Name of Allah, The Most Merciful, The Bestower of Mercy.

Four thousand Khawarij were fought against by Ali, Ameerul Mumineen, may Allah be pleased with him, at Nahrawan and none of them survived except nine. Two men from them departed to Sijistan and through them appeared the Khawarij of Sijstaan; two men from them departed to Yemen and through them appeared the Ibadiyyah of Yemen; two men from them departed to Oman and through them appeared the Khawarij of Oman; two men from them departed towards other regions of the Arabian Peninsula and through them appeared the Khawarij of those regions. A man from them departed to Syria. This was one of the reasons behind their settlement in different lands. Thereafter, they became different murderous sects upon divergent creeds.

Al-Farq Bayn Al-Firaq. page 80