The Hausas refused to be federated with southerners and other non-Muslims whom they considered "Kafiri".    From Wordnik.com.  [Yahoo! News: Business - Opinion] Reference

For Kochhar (2000: 186, 222) "non-RgVedic Aryans" (presumably he means speakers of Dardic or Kafiri languages) arrived around 2000 (or 1700) BC, to be followed by the "actual RgVedic people" in around 1400 BC.    From Wordnik.com.  [The Civic Platform - A Political Journal of Ideas and Analysis] Reference

Meanwhile, the languages of the Kafiri-Nuristani and Dardic language families, spoken in northeastern Afghanistan and northern Pakistan, have forms of Indo-Aryan that are considered earlier than their counterparts in Avestan and the RgVeda (Witzel 1995a.    From Wordnik.com.  [The Civic Platform - A Political Journal of Ideas and Analysis] Reference