Massive pro- and anti-government rallies take place in crisis-striken Venezuela Venezuelan opposition leader Juan Guaido calls for huge May Day protests to pile pressure on President Nicolas Maduro as the United States says it is prepared to take military action to stem the crisis in the South American nation. Pro- and anti-government rallies are taking place, a day after violent clashes erupted in the capital following Guido's call on the military to rise up against Maduro, who claimed the insurrection had failed.