L1 users: 26,700 (2005 census). Total users in all countries: 82,300.
Savannahkhet province: Sepone district; Khammouan province: Boulapha district.
Leun (Kaleu, Leung), Tri (Chali, So Tri, So Trii). Partially intelligible with Western Bru [brv] of Thailand. The Mangkong dialect in Viet Nam and eastern Laos is a dialect of Eastern Bru, different linguistically from the Mangkong that are the same as So [sss] of Thailand. Mangkong is also an ethnic group.