Greenpeace climbers are hanging of a bridge in Nuevo Laredo, where they intercepted a trainload of USA maize as it tried to enter Mexico in response to fresh evidence that the US was dumping Monsanto's genetically engineered crops across the border contradicting international agreements. The banners are showing a cob of corn crossed out with the word "genetically modified" in Spanish. This action precedes the WTO meeting in Cancun next month.