In Washington, US Secretary of State Rex Tillerson expressed concerns to reporters Wednesday that the "government of Maduro is violating its own constitution and is not allowing the opposition to have their voices heard, nor allowing them to organize in a way that expresses the views of the Venezuelan people". It is a touchy date in Venezuela, where Chavez and Maduro have built a politics of populist, left-wing nationalism around the fight for independence from colonial Spain and around the hero of the struggle, Simon Bolivar.
In advance of today's protests, the region's eyes were on Venezuela.
"I participate in these protests, out of a sense of responsibility for being Venezuelan". In February, the Supreme Court, widely understood as being controlled by the government, upheld leading opposition figure Leopoldo Lopez's 14 year jail sentence.
Persistent shortages of food and medicine have left many Venezuelans miserable, but the threat of violence has limited the ability of Maduro's opponents to attract massive crowds.
The Bolivarian militias that were created during the reign of Hugo Chavez will be armed by the Venezuelan government, were some 100,000 in attendance, but loyalists are estimated to number somewhere around 400,000.
In Latin America, where other governments are increasingly alarmed by Venezuela's instability, 11 countries including Brazil, Mexico and Chile issued a statement Monday condemning the deaths of protesters and urging the security forces to show restraint. The national guard, made up of civilians, primarily focuses on internal security in addition to the army, the navy and the air force.
Later on Wednesday in the opposition hotbed of San Cristobal near the Colombia border, university student Paola Ramirez died after being shot by men pursuing her and her boyfriend, according to relatives and witnesses. "We'll see who tires out first". "I tried to protect her as much as I could", he added, sobbing in front of her body.
"This is a call for reflection to officials of the armed forces to think about the role they are playing in this moment of Venezuela's history", he said.
This new wave of protests began early this month after the pro-government Supreme Court tried to dissolve the opposition-controlled congress - only backtracking amid global pressure.
Maduro's government has been increasing its suppression of protests over the past weeks, with Caracas-based nongovernmental agency Foro Penal reporting five deaths and at least 538 arrests at protests this month. "There are a lot of people in the opposition and they are full of courage".
Venezuela has been rocked by unrest since March 30, when Maduro's camp moved to consolidate its control with a Supreme Court decision taking over the power of the opposition-majority legislature.
The court's move nonetheless fueled long-simmering anger over the ruling Socialist Party's handling of the economy.
Santos' sensitivity towards Venezuela is because millions of Colombians and Venezuelans have dual citizenship and the neighboring country played a major role - and could be a major spoiler - in peace talks with Marxist rebels groups FARC and ELN. The Caracas subway system announced it was closing 28 of its busiest stations, out of a total of 64, particularly those along the path of the opposition's march.
The opposition will congregate at more than two dozen meeting points around Caracas and attempt to converge on the office of the state ombudsman, a guarantor of human rights.
"It is a constitutional right to call for peaceful protests, and they should not put the physical safety of protesters at risk", she said in a statement on Twitter.