Updated

A group of sex offenders is fighting back against a California city ordinance that bans them from opening their doors to children on Halloween, with their attorney comparing the ban to the discrimination faced by the Jews during Nazi Germany.

The Ventura County Star reports the federal lawsuit was filed Friday on behalf of five registered sex offenders, three of their spouses and two of their children. It alleges the ordinance passed by the city of Simi Valley violates the First and 14th Amendments because it "suppresses and unduly chills protected speech and expression."

The ordinance requires the offenders to post signs on their front doors saying, "No candy or treats at this residence." It also bars them from displaying Halloween decorations or having exterior lighting on their property from 5 p.m. to midnight on Oct. 31.

Attorney Janice Bellucci tells The Los Angeles Times she plans to ask the judge for an injunction to keep the city from enforcing its new law this Halloween. Bellucci, who heads an advocacy group called California Reform Our Sex Offender Laws, says her clients were particularly upset by the requirement to have a sign in the front yard.

"To us, it's similar to branding," she told the paper. "We can think of what happened in Nazi Germany, where Jews had to appear in public wearing yellow stars."

City officials tell The Los Angeles Times they modeled their new ordinance after similar preemptive laws in other parts of Southern California.

Simi Valley City Attorney Marjorie Baxter tells The Ventura County Star that the lawsuit's claims the ordinance violates the sex offenders' rights are groundless.

"We thoroughly researched the ordinance and I don't feel the lawsuit has any merit, and we will defend it vigorously," she told the paper.

Click for more from The Ventura County Star. 

Click for more from The Los Angeles Times.

The Associated Press contributed to this report.