PHOENIX -- The Maricopa County Sheriff's Office is investigating a drop house near Osborn Road and 60th Avenue in west Phoenix.
Sheriff Joe Arpaio told The Associated Press that investigators developed a tip that led to the drop house.
Sheriff's deputies and a SWAT team surrounded the home Friday morning and brought out more than 30 people.
Chopper video showed them sitting on the curb restrained with plastic handcuffs.
Arpaio said the suspected illegal immigrants had been held in a boarded-up room for several days.
Four smugglers and 36 people held hostage were taken into custody.
No injuries were reported.
The neighborhood is blocked off while the investigation continues.
The Associated Press contributed to this report.