Thousands of demonstrators hit the streets of 400 cities across 40 countries in the third annual March Against Monsanto rally against genetically-modified organisms (GMO) on Saturday.

About 2,500 people rallied in Basel and Morgues, Switzerland, outside the head offices of Monsanto, MSN News reported.

In Paris, France, 3,000 demonstrators that included activists from environmental group Greenpeace and anti-capitalist group Stop Tafta waved placards against Monsanto's pesticide brand Roundup calling it carcinogenic.

In Strasbourg, 1,000 French demonstrators gathered outside the European Parliament and held a minute of silence for existing and future victims poisoned by pesticides, MSN reported.

In another French city, Rennes, demonstrators also denounced Monsanto and pesticide company Roundup, who use an ingredient that was recently classified as "probably carcinogenic to humans" by the World Health Organization based on a study by the International Agency for Research on Cancer.

In Burkina Faso, 400 marchers protested against Monsanto cotton seed introduced in the African country in 2003. They demanded a 10-year moratorium on the planting of Monsanto seeds.

In the Nebraska Capitol, protesters accused Monsanto of killing people.

"They are committing mass genocide by sneaking their genetically modified organisms into our food without our consent," activist Rachelle Duryea said of Monsanto, according to ABC 8 of Lincoln, Nebraska.

Monsanto released a statement in response to the rally.

"The 22,000 people of Monsanto are committed to having an open dialogue about food and agriculture. We're proud of the work we do, and we're eager for people to know more about us. We're also proud of our collaboration with farmers and partnering organizations that help make a more balanced meal accessible for everyone," the statement said, according to ABC 8. "Our goal is to help farmers do this in a more sustainable way using fewer resources and having a smaller impact on the environment. We know people have different points of view on these topics, and it's important that they're able to express and share them."

The March Against Monsanto was launched by the group Occupy in 2013.

The global rallies followed Monsanto President and Chief Operating Officer Brett Begemann's speech before investors attending the BMO Capital Markets 10th Annual Farm to Market Conference in New York on Wednesday.

"The future of agriculture belongs to those who sustainably steward every field - with precise, integrated solutions to enhance the productivity of every seed on an increasingly static footprint," Begemann said, according to a press statement from Monsanto. "Companies with a track record of innovation and with the vision and discipline to execute will succeed in this new space."