Siah Ettefaq-e Pain (, also Romanized as Sīāh Ettefāq-e Pā’īn; also known as Sīāh Tefāq) is a village in Birk Rural District, in the Central District of Mehrestan County, Sistan and Baluchestan Province, Iran. At the 2006 census, its population was 333, in 73 families.
