Races in lane coming out of East Berlin (6)

I believe the answer is:

tribes

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'races' is the definition.
(I've seen this before)

I don't understand how the remainder of the clue works.

(Other definitions for tribes that I've seen before include "Racial groups living in communities headed by chiefs" , "Social groups in traditional societies" , "Clans" , "Groups of people related by blood" , "Groups of families in traditional societies" .)

I've seen this clue in the Irish Times and the Irish Times (Crosaire).

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