§ Of the Sindar The Silmarillion

But as the third age of the captivity of Melkor drew on, the Dwarves became troubled, and they spoke to King Thingol, saying that the Valar had not rooted out utterly the evils of the North, and now the remnant, having long multiplied in the dark, were coming forth once more and roaming far and wide. 'There are fell beasts,' they said, 'in the land east of the mountains, and your ancient kindred that dwell there are flying from the plains to the hills.'