Protesters march against GMO giant Monsanto in 430 cities

Protests against seed giant Monsanto are getting under way across the U.S. and in dozens of other countries.

"March Against Monsanto" organizers say they're calling attention to the dangers posed by genetically modified food and the companies that produce it. Protests are planned in more than 250 cities Saturday.

Genetically modified plants are grown from seeds engineered to resist insecticides and herbicides, add nutritional benefits and improve crop yields.

Some believe they can lead to health problems and harm the environment. Opponents have pushed for mandatory labeling, though the federal government and many scientists say the technology is safe.

Monsanto Co., based in St. Louis, said Saturday that it respects people's rights to express their opinion, but believes its seeds help farmers produce more food, while conserving water and energy.