A little before noon on Tuesday, protesters stood silently on a Chicago street, blue duct tape covering their mouths. Then, linking arms, they began to slowly walk forward.

An activist with Fight for $15, a group that advocates raising the minimum wage,was filming the march and explained that the protesters were headed to McDonald’s Hamburger University,where the fast-food company trains managers. When the marchers got there, the tape came off their mouths, and the chants began.

“You will hear us today,” said Adriana Alvarez, who introduced herself as a McDonald’s worker and a single mother from Chicago. “We will not stay silent anymore.”

Like the other McDonald’s workers surrounding her, Alvarez had gone on strike to demand that the company do more to address sexual harassment. At franchises nationwide, McDonald’s employees walked out at noon on Tuesday and didn’t return for the rest of the day in what organizers said was the first multistate strike to target workplace sexual harassment.

According to the Associated Press, Tuesday’s protests took place in six cities: Chicago; San Francisco; Los Angeles; St. Louis; Kansas City, Mo.; and Durham, N.C.

“We’ve seen in the news that sexual harassment is happening to others at major corporations like CBS, and now Hollywood actresses have filed lawsuits against their CEOs and media moguls,” Alvarez said. “Now, more than ever, it is imperative that fast-food workers take action and use our voices in the same way — to hold McDonald’s and other fast-food chains accountable. The public does not know what we go through behind the counters, the cash registers, even in the bathrooms, the janitor’s closets. But today, the world will find out more.”

The workers who led Tuesday’s strike are demanding that the company hold mandatory training for managers and employees and create a secure system for responding to sexual harassment complaints. They also want the company to form a committee where workers and representatives of women’s rights groups can play a role in addressing sexual harassment.

The strike comes several months after multiple women chose to take legal action against the company. In May, 10 McDonald’s workers filed complaints with the U.S. Equal Employment Opportunity Commission, alleging that they faced pervasive sexual harassment and a climate in which women who spoke up were retaliated against or ignored. The Time’s Up Legal Defense Fund, which was created this year to support women who report sexual harassment, paid for their legal representation.

The complaints spanned nine cities but followed a similar theme, The Washington Post reported. In Kansas City, Kim Lawson said her manager had sent her home early when she rejected his sexual advances. In St. Louis, Breauna Morrow said she was 15 years old when one of her co-workers started making comments about her body and asked her, “Have you ever had white chocolate inside you?” According to the complaint, she notified her manager, who told her that she would “never win that battle.” In New Orleans, Tanya Harrel said that her supervisor hadn’t taken her seriously when she reported that a co-worker had grabbed her buttocks. She said that when another co-worker tried to have sex with her in the restaurant’s bathroom, she was too discouraged to bother reporting it.

At the time of the May complaints, a spokesman for McDonald’s said that the company wouldn’t tolerate sexual misconduct and that he was confident that the corporation’s franchisees took allegations of harassment seriously. But some of the employees who went on strike Tuesday said that they haven’t seen anything change in the wake of the EEOC complaints.

“They were courageous, they told their stories, and guess what McDonald’s did?” Alvarez said at Tuesday’s protest. “Nothing.”

McDonald’s did not comment on the strike but told the AP, “We have policies, procedures and training in place that are specifically designed to prevent sexual harassment at our company and company-owned restaurants, and we firmly believe that our franchisees share this commitment.”

The nature of the sexual harassment strike against the fast-food giant has precedent. Annelise Orleck, a professor of history at Dartmouth College who has also done public relations work for striking McDonald’s workers, told the New Republic that corset-makers in Kalamazoo, Mich., had walked out of work in protest of sexual harassment in 1912.

As Alvarez noted in her speech, much of the conversation around the #MeToo movement has focused on celebrities and high-profile figures. But researchers have found that workers in low-wage service jobs, whose stories don’t get as much attention, are particularly vulnerable to sexual harassment. A 2016 survey by the public-opinion polling firm Hart Research Associates found that 40 percent of women in the fast-food industry had experienced unwanted sexual harassment at work. Of those women, 42 percent said they felt as if they needed to accept the harassment because they couldn’t afford to lose their jobs.

Standing outside Hamburger University, an otherwise ordinary office building emblazoned with the trademark golden arches, protesters on Tuesday held up banners that said, “#MeToo McDonald’s” and “McDonald’s: Sexual harassment is unacceptable.” Some wore their uniforms, painted with handprints that represented unwanted groping. One woman held a sign with Ronald McDonald’s face and the words “Time’s up, clown.”

“We’re saying enough to sexual abuse and harassment,” a McDonald’s worker named Theresa Cervantes told the crowd. “We all demand dignity and respect. We all deserve a clean and protected environment.