LOS ANGELES (AP) — Authorities seized more than 100 guns in Southern California as part of a five-day sweep to remove firearms and ammunition from people who are no longer legally allowed to own or possess them, officials announced Tuesday.

The operation last week in Los Angeles County also included 13 arrests, California Attorney General Rob Bonta said during a news conference. Investigators also took nearly 50,000 rounds of ammunition and 87 high-capacity magazines away.

People prohibited to own or posses firearms in California include those who were convicted of a felony or a violent misdemeanor, placed under a domestic violence or other restraining order, or suffer from serious mental illness. The state established a system in 2006 — the first to do so — that tracks firearm owners who fall into one of those prohibited categories.

Authorities found 55 handguns, 19 rifles, 15 shotguns, 17 assault weapons, and eight ghost guns as part of the sweep across 51 cities in LA County. A similar operation was conducted in January in the San Francisco Bay Area, where 30 firearms were seized and eight people were arrested.

“Those are weapons and ammunition that are no longer available to harm the public,” Bonta said.