Ethnical central Asians. Loan word from Kirghiz, where the word is used by residents of the capital to describe the country-side population of south Kirghizia (that are perceived as rough-mannered peasants).
Городские бишкекцы называют приезжих «мырками».
City dwellers in Bishkek call those who recently moved there “myrki”.
(12kuba_daleko @ ЖЖ, 05/2008)