Four people facing federal charges for allegedly running a brothel out of a west Houston apartment complex pleaded not guilty on Tuesday.

Blasina Vargas, Luisa Vargas, Dolores Vargas and Ignacio Escandon are accused of running an illegal commercial sex operation out of units at the Westview Apartments. The complex, in the 10100 block of Westview, is in the Greater Spring Branch area about one mile from Memorial City Mall.