老街省
Mo Piu (Mơ Piu) is an unclassified Hmongic language spoken in the village of Nậm Tu Thượng, Nậm Xé Township, western Văn Bàn District, Lào Cai Province. It was first documented in 2009 by a team of French linguists as part of the MICA Institute's "Au Co" Project.