Thousands of Venezuelans heeded a fugitive opposition leader's call for a march in defiance of a ban Tuesday as security forces moved in to stop them and the government planned its own rallies. As opposition protesters converged on the Plaza Brion in eastern Caracas, where the march was to start, supporters of President Nicolas Maduro were set to rally nearby, raising the risk of a confrontation. Tensions are high after two weeks of protests in the oil-rich country, led by students angry over rampant crime, deteriorating living conditions and jailings of demonstrators. The protests began in provincial cities and moved to Caracas. Maduro has blamed opposition leader Leopoldo Lopez for violent clashes that left three people dead last week, and ordered his arrest on charges of homicide and inciting violence. Standing in the way of opposition protesters on Tuesday were three rings of national police, backed by a second line of National Guard anti-riot units. Light armored vehicles also were deployed in the relatively affluent area of the capital ahead of the march, which was banned by Maduro's government. 'They will not pass' "Not one single opposition march is going to enter the territory of Libertador municipality," said National Assembly President Diosdado Cabello, referring to the city's western downtown district, where the opposition march was to end. "They will not pass. It is not authorized," Cabello said late Monday on his new nightly television program. The opposition protesters turned out anyway. Some carried signs that read: "24,763 violent deaths in 2013. We are more than a statistic." Carlos Vecchio, political coordinator of Lopez's People's Will party, said it was the state's responsibility "to guarantee that this comes off in the best possible way." Lopez, who has been out of public view since the government ordered his arrest last week, appeared Sunday on a video linked to his Twitter account inviting supporters to join him in a march on the Justice Ministry. "If there is some decision to illegally jail me, I will be there to assume that persecution," he said. "Let's all go dressed in white to signify our commitment to peace. I invite you to walk to a point and from there I will go alone. I don't want to risk the life ... of any compatriot," he said. He indeed appeared in the Plaza Brion on Tuesday, wearing all white. He climbed on a statue with the Venezuelan flag in his hands, to the delight of cheering protesters. On Monday, authorities raided Lopez's party headquarters, but until now the 42-year-old Harvard educated economist has eluded capture. Under the slogan "the exit," Lopez and other opposition leaders have pushed for anti-government street protests to force a "constitutional change." There is no provision for recall elections until April 2016, and Maduro, who was elected in April 2013, has said he will never resign. Students and other opponents of Maduro are angry about living conditions -- rampant crime, dismal job prospects, high inflation and other woes -- in the country with the world's biggest proven oil reserves. The confrontational approach has aroused misgivings within the opposition coalition formed in 2012 to defeat the late Hugo Chavez. But Henrique Capriles, the two-time opposition presidential candidate and governor of the state of Miranda, has said he would take part in Tuesday's march even though he does not think the time is ripe to try to force the government from power. "We may have differences but we feel solidarity," Capriles said. - Tense US-Venezuela ties - The tensions generated by the protests have spilled into the international arena as well. On Sunday, Maduro ordered the expulsion of three US diplomats, accusing them of meeting with student leaders under the guise of offering them visas.    The United States denied the allegations as "baseless and false," and urged the government to engage all parties in a "meaningful dialogue." Foreign Minister Elias Jaua identified the Americans declared "persona non grata" as Breeann Marie McCusker, Jeffrey Gordon Elsen and Kristofer Lee Clark, all said to be second secretaries at the US embassy. Venezuela's relations with Washington, long strained under Chavez, have remained sour and distrustful under Maduro, who has hewed closely to his predecessor's socialist policies. In late September, Maduro kicked out three other US diplomats, on accusations of conspiring with government opponents. The two countries have had no ambassadors since 2010. Various Latin American leaders closed ranks behind Maduro, while regional organizations like Celac, Unasur and countries like Mexico and Panama urged Venezuelans to resolve their differences through dialogue. The secretary general of the Organization of American States, Jose Miguel Insulza, called on all sides to refrain from violence, warning it would further polarize "the delicate political moment that the South American country is living." Tension is likely to brim throughout the day because both rallies, unlike previous ones, are scheduled to culminate in the same part of Caracas. Shortly after Lopez said he would take part in the anti-government rally, Maduro called a rally by employees of the state-run oil company that is to end at the presidential palace.