The phrase "a tribe called" is correct and usable in written English.
It can be used when referring to a specific group or community, often in a cultural or social context.
Example: "I recently attended a gathering organized by a tribe called the Earth Keepers, who focus on environmental conservation."
Alternatives: "a group known as" or "a community referred to as".
The Ossetians are descendants of a tribe called the Alans.
It was in the Oma Valley in Southern Ethiopia, where there's a tribe called Kara.
Targaryen is the first female war leader of a tribe called the Dothraki, in the complicated maze of competition between would-be rulers.
Ever since a tribe called the Yojin was driven into Manchuria in the 16th century, the Korean side of the river has been inhabited only by Koreans.
There had never been a tribe called "the Arabs" — the term was popularized in the nineteen-fifties, as part of Gamal Abdel Nasser's pan-Arabism.
They are of Armorican origin (modern day Brittany and Normandy) from a tribe called the Coriosolitae, who were based around Rance in the area of modern-day St Malo and Dinan.
The most distinctive aspect of the landscape was vast beds of tall reeds, resembling bamboo, with which the marsh dwellers, a tribe called the Madan, built large, vaulted island houses.
Jay, a 30-year-old party organizer in Brooklyn, belongs to a tribe called BMP -- he won't say what the letters stand for -- that he describes as a big, heterogeneous family.
And in Ghost Hawk, young John Wakeley has to sit in the puritan meeting house listening to the report of an attack on a tribe called the Pequots, whose village is set on fire in the dark as they lie sleeping.
This confirms the overseas provenance of the Iapyges from the Balkans, the more so because there existed in Illyria a tribe called the Iapodes and because a people known as the Iapuzkus lived farther north, on the Adriatic coast of Italy.
Members of a tribe called the Tungus carried smoke pots with them wherever they went, while another native people, the Voguls, retreated into smoke-filled huts for the summer months and became dormant, doing most of their hunting and travelling in the wintertime.
