Around 300 women rural residents in Brazil burst into a property owned by the US company Monsanto and destroyed a plant nursery and crops containing genetically modified corn, their organization said.

The women were protesting what they saw as environmental damage by the crops.

They trashed the plants within 30 minutes and left before police arrived at the site in the southern state of Sao Paulo, a member of the Landless Workers' Movement, Igor Foride, told AFP.

The Brazilian government had "caved in to pressure from agrobusinesses" by recently allowing tinkered crops to be grown in the country, he said.

In Brasilia, a protest by another 400 women from an umbrella group, Via Campesina (the Rural Way), was held in front of the Swiss embassy against Syngenta, a Swiss company that is selling genetically modified seeds in Brazil.

The demonstrators called attention to an October 2007 incident in which private guards working for Syngenta killed a protester taking part in an occupation of land owned by the company.

Via Campesina said in a statement that "no scientific studies exist that guarantee that genetically modified crops won't have negative effects on human health and on nature."

It added that on Tuesday, another 900 of its members had entered a property owned by the Swedish-Finnish paper giant Stora Enso and ripped out non-modified eucalyptus saplings they claimed were illegally planted.