The Maricopa County Sheriff's Office will shut down all six of its jails Saturday because of a large protest expected in the evening.

Sheriff's officials expect a protest by 1,000 to 4,000 activists at Tent City Jail near 29th Avenue and Durango Road in Phoenix, officials said. The shutdown means family and friends won't be allowed to visit inmates at the jails for the entire day.

Puente Arizona and Unitarian Universalist Association officials said they will hold a peaceful vigil to protest Tent City and Senate Bill 1070. The Unitarians are holding a four-day convention at the Phoenix Convention Center with workshops, speakers and planned demonstrations.

Steve Carl, 67, a spokesman for the Unitarians, said the association discussed having an assembly in Arizona two years ago with the introduction of SB 1070 and decided to take action closer to the U.S. Supreme Court ruling on Arizona's immigration law. The Supreme Court is expected to release its ruling soon.

"The main point is to show national disapproval of Arizona's immigration laws," Carl said. "Arizona is at the forefront of human violations and leading the way for other states in the country."

Sheriff Joe Arpaio plans to be present at the demonstration to defend Tent City and his jail policies, officials said.

Several members of the convention gathered near Heritage Square on Thursday night for nearly an hour singing songs, praying and wearing shirts and showing banners.