President Hugo Chavez said he had "no choice" after Colombia accused Venezuela of being a haven for guerrillas - a charge he denies.

He said that he was acting "out of dignity" in severing ties.

He also ordered the military to be on maximum alert on Venezuela's border with Colombia.

President Chavez made his announcement shortly after a meeting of the Organisation of American States (OAS) in Washington, at which Colombia presented videos, maps and photos to back up its claims that Marxist Farc and ELN rebels have bases in Venezuela.

The Colombian ambassador to the OAS, Luis Alfonso Hoyos, said the material was clear evidence that some 1,500 Colombian rebels were sheltering at numerous camps inside Venezuela.

Mr Hoyos said the photographs showed that the rebels had 39 camps in Venezuela and that top guerrilla commanders were resident there.