Lilian Tintori and Patricia Gutierrez, both wives of jailed political leaders and advocates of hard-line tactics against the government, led a rally of thousands in the Venezuelan capital on Saturday, blocking the city's main thoroughfare.

Tintori, wife of jailed opposition leader Leopoldo Lopez, has called for civil disobedience in Venezuela as, she claims, there are no democratic options left. Former congresswoman Maria Corina Machado and Patricia de Ceballos, opposition mayor of San Cristobal, also took part.

Machado had called for an extraordinary session of the National Assembly, which is to take place on Sunday, to impeach Maduro: "Tomorrow in its extraordinary session, the National Assembly should declare there is a dictatorship in Venezuela; it should begin tomorrow the process to impeach Nicolas Maduro." The opposition won control of the assembly in elections last December.

Machado also reminded the military that their "only duty is to exclusively serve the nation and not a political project," in reference to Maduro's appointment in July of Defense Minister Vladimir Padrino Lopez to a newly created role close to that of co-president.

At the same time, Maduro increased the power and autonomy of the military over civilians. The armed forces were put in charge of a new food supply system, the Great Sovereign Supply Mission, aimed at alleviating crippling shortages. The moves ceded yet more power to the military, which was already involved in a range of state and institutional activities from banking to imports.

The protest on Saturday came at the end of the week when the election board halted a process for a recall referendum which would have challenged Maduro's presidency. The board referred to government allegations of fraud during an initial signature drive for the referendum. The decision left Maduro on track to complete his six-year term as president, after succeeding Hugo Chavez, who died of cancer in 2013.

"Under no circumstances are we going to let them overthrow the government," Diosdado Cabello of the ruling Socialist Party said at a press conference on Saturday.

Venezuela has some of the world's largest oil reserves but is undergoing an unprecedented economic crisis. Maduro has blamed the fall in the price of oil for the country's woes, but his critics blame government mismanagement. Maduro has also accused the US of waging an "economic war" against his government.

The opposition Democratic Unity coalition has announced nationwide rallies for next Wednesday.

Airspace investigation for Colombia

Separately, Maduro has ordered an investigation after Colombia's Avianca airline reported a flight from Spain was approached by at least one warplane on Friday.

The Colombian Defense Ministry said the aircraft, which was flying from Madrid to Bogota, was briefly approached by a Venezuelan military plane. Luis Carlos Villegas, Colombia's defense minister, said he had spoken to his Venezuelan counterpart, who had promised a full investigation.

After diplomatic conversations, Maduro ordered an investigation.

In response, Avianca said it had suspended flights to and over Venezuela. "We're waiting for them to guarantee the security conditions required to operate," said Gilma Usuga, an Avianca spokeswoman.

Relations between the South American neighbors have been tense in recent years, with Caracas accusing Colombia of provocation and Bogota accusing Venezuela of supporting Colombian guerrillas.

jm/cmk (EFE, Reuters)