The earliest inhabitants of the region are assigned to the Middle Pleistocene period (781,000 to 126,000 years ago) in the Rongram valley of Garo Hills. The Paleolithic sites, which used handaxe-cleaver tools, have affinities to the Abbevillio-Acheulean culture. Other Paleolithic sites include those in the Daphabum area of Lohit district in Arunachal Pradesh which used stone tools from metamorphic rocks. The cave-based Paleolithic sites at Khangkhui in Ukhrul, Manipur, are placed in the Late Pleistocene period.