BUENOS AIRES, Argentina (AP) Argentine farm groups suspended grain exports and relaunched road blockades nationwide Wednesday, trying to overturn export taxes that have sparked waves of protests.

``We're not letting trucks carrying any kind of grains pass on the roads,'' said Alfredo Robles, a regional director for the Argentine Rural Confederation, to The Associated Press. ``As of Wednesday at midnight, no trucks carrying meat destined for slaughter can pass either.''

Argentina is the world's fourth largest exporter of beef and the third largest exporter of soy.

The supply of cattle to the country's main stockyard had already fallen by nearly 20 percent Wednesday, according to stockyard officials.

President Cristina Fernandez's government says the increased export taxes _ reaching more than 40 percent on most grains _ are needed to keep farmers producing wheat, corn and cattle for the local market instead of trying to capitalize on soaring world prices for soy.

The farmers will continue protesting until June 2, Robles said, and the four main farm group will then take the issue to the Congress and the Supreme Court.

The government canceled a meeting planned for Monday with farm leaders, prompting the resumption of protests that have periodically disrupted food supplies over the past three months.

Former President Nestor Kirchner, husband of current President Cristina Fernandez, issued a statement late Tuesday comparing the farmers' protests to actions that led to the 1955 overthrow of President Juan Peron and to a 1976 coup that established a military dictatorship. (Copyright 2008 by The Associated Press. All Rights Reserved.)