Police used tear gas in Venezuela's capital on Wednesday to stop thousands of protestors from reaching electoral commission headquarters to press their demands that it proceed with the referendum already sought in an opposition petition.

"Maduro Out!," yelled some protesters, referring to referendum on whether to recall Maduro from office.

Referendum 'not viable,' says Maduro

Caracas' urban train stations were closed for "operational reasons" on Wednesday, preventing some protesters from joining the demonstration.

Venezuelans defiant, says Capriles

Heading the protest was opposition leader Henrique Capriles, who warned that many Venezuelans were ready to defy the president's emergency powers.

"If Maduro wants to apply this decree, he needs to start preparing tanks and warplanes, because he'll have to apply it by force," said Capriles.

Maduro's 60-day emergency was imposed on Monday amid critical food and energy shortages and what he has termed US interference working with Venezuela's "fascist" right.

The opposition-controlled National Assembly subsequently rejected Maduro's emergency powers. However, the chamber's decisions have regularly been overruled by the country's government-leaning Supreme Court, and some believe it will be the case again.

AOS head scathing

Wednesday's protest coincided with scathing criticism of Maduro from the head of the Organization of American States (AOS).

Capriles says Venezuelans ready to defy emergency

In an open letter, AOS Secretary General Luis Almagro warned Maduro that he risked becoming a "petty dictator" if he impeded the recall referendum.

"You have an obligation to public decency to hold the recall referendum in 2016, because when politics are polarized the decision must go back to the people. That is what the constitution says," Almagro said.

He went on to accuse Maduro of "betraying" Venezuelans by failing to submit himself to the "scrutiny of your people."

On Tuesday, Maduro declared that the opposition-backed referendum bid was "not viable."

A recall referendum must be held before 10 January 2017 to trigger new elections. Beyond that, a recall outcome would transfer power to Vice President Aristobulo Isturiz.

Change, says survey

A recent survey by the polling firm Datanalisis found that seventy percent of the population want a change of government.

Venezuela is also facing rampant crime and corruption, while hyperinflation climbed to 180 percent in 2015, despite the country having huge oil reserves.

Last year, Venezuela's gross domestic product shrank by 5.7 percent, and this year GDP is forecast to contract eight percent.

ipj/rc (AFP, AP)