Nearly 200 marchers paraded Saturday through downtown Santa Rosa, calling for labeling and bans on genetically modified food products as part of demonstrations planned in more than 400 cities worldwide.

The March Against Monsanto came less than a month before Washington state voters decide the fate of a GMO labeling law, similar to one that was defeated last year in California.

"It's our right to know," Maryam Kazemi of Petaluma said about why she marched in the demonstration that wound from City Hall to the Burbank Gardens neighborhood and back down Fourth Street. She said "people are waking up" and wanting to learn what's in their food.

The local march, the second such event this year, was sponsored Sonoma County Label GMOs and Occupy Sonoma County GMO Campaign.

The demonstrators, led by the 10-piece Hubbub Club marching band, passed beneath a dozen seniors watching from balconies at the multi-story Bethlehem Towers apartments on Tupper Street, strode before Rosie the Trolley as it stopped by the Santa Rosa Library and waved to diners seated outside at restaurants and taverns along Fourth Street.

Washington's Initiative 522 is the latest high-stakes effort in the GMO fight, drawing huge contributions of money and effort from around the nation.

The Seattle Post Intelligencer reported last week that about 72 percent of the $4.7 million donated in support of the initiative has come from out of state.

Meanwhile, five corporations and a food manufacturers' trade group have been the biggest backers in raising $17.2 million to defeat the initiative, the newspaper reported. Of those groups, Monsanto, the St. Louis-based biochemical giant, has donated $4.8 million.

Regardless of the outcome of the Washington vote, GMO labeling is coming, said Thomas Cooper, a march organizer with Occupy Sonoma County. He noted that Whole Foods already has decreed that by 2018 all products must be labeled if they contain GMOs.

"They're on the wrong side of history," Cooper said of labeling opponents.

Monsanto maintains that GMO products have been used commercially since 1996 without any scientific evidence of harm to humans, animals or the environment. Its materials state that regulatory agencies in 59 countries "have conducted extensive scientific reviews and confirmed the safety of GM crops."

The materials also call a myth the suggestion that the company exerts undue influence on governments, or that a conspiracy exists because people who worked for Monsanto get hired by the government, or vice versa. Instead, it suggested that switching careers is hardly unusual and that both the public and private sectors benefit "when employers have access to the most competent and experienced people."

Such assertions drew a quick retort from Cooper.

If it's so safe, then label it," he said.

He insisted that Monsanto's "revolving door" of officials moving into and out of government is largely about obtaining access and influence.

"They have people that aren't out for the best interests of the American people and the environment," he said.

Marchers also maintained that countries across Europe and Asia have imposed much stronger GMO regulations than the United States.

"They are all labeling or banning it," said Jessica Denning, a Sacramento member of the anti-GMO group Moms Across America.

As an example of the growing concerns, Cooper pointed to news reports of an eastern Washington alfalfa farmer whose crop inexplicably became tainted with a genetically engineered alfalfa. According to Reuters news service, hay brokers said they don't want GMO in the crop because so many foreign buyers won't accept it.