About 2,000 government and non-governmental officials will attend the five-day UN conference in Bonn to discuss global protection measures for the transfer of genetically modified plants, including rice and soya.

The issue has become particularly sensitive due to a recent surge in food prices which has sparked anger and protests in some developing countries.

The experts will try to agree on ways to help implement a UN agreement on the trading of living genetically modified organisms called the Cartagena protocol.

In Europe, consumers are fairly sceptical about GM crops but the biotch industry says its products are as safe as non-GM equivalents.

The conference, which starts on Monday, precedes a bigger summit next week on biodiversity in Bonn where some 4,000 international experts and government ministers will try to agree on ways to slow the rate of extinctions.

"We want biodiversity to be part of humanity's wealth and a precondition to overcome hunger," said Greens EU lawmaker Friedrich-Wilhelm Graefe zu Baringdorf who was on the march.

"We demand that all other activities, which probably boost industry's profits, do not endanger food security for future generations," he told Reuters Television.