Caracas Mayor to Appeal Coup Plot Charge

The mayor of Caracas, who was detained and charged with plotting to overthrow Venezuelan President Nicolas Maduro's government, will appeal the "baseless" allegations, his lawyer said on Saturday.

Antonio Ledezma's arrest is part of a growing crackdown on high-profile opponents of the socialist president as OPEC member Venezuela struggles with a deepening economic crisis.

"His defense will be using everything we have at our disposal," attorney Omar Estacio told AFP.

"For now, we are planning an appeal because the allegations against the mayor are baseless and illegal."

A leading opponent of Maduro, the 59-year-old mayor was arrested on Thursday for his alleged involvement in a conspiracy "to organize and carry out violent acts against the government," prosecutors have said.

Opposition leader Henrique Capriles called on the government to produce evidence of the supposed conspiracy.

"Does Maduro think that putting everyone in prison is going to get him 50 popularity points or that he's going to win elections?" the two-time presidential candidate asked.

Maduro, who has accused the opposition of trying to topple him several times since his April 2013 election, said that the mayor was detained over a coup plot financed by the United States.

Washington dismissed the "baseless and false" claims.

The UNASUR South American bloc is planning to hold an extraordinary meeting of foreign ministers on the situation in Venezuela.

Organization of American States Secretary General Jose Miguel Insulza said Ledezma's arrest "has caused alarm" due to the way he was detained.

He called on the government to "stop those acts that lead to a spiral of polarization that envelops Venezuelan society."

Last week, Ledezma and other opposition figures signed a newspaper advertisement calling for a democratic transition in Venezuela.

Maduro - an elected socialist whom critics say has amassed more and more power while pressuring out opposition - has seen his popularity sink to 20 per cent amid a growing shortage of basic goods, massive lines outside supermarkets and soaring inflation of almost 70 per cent in the recession-hit country.

Plunging oil prices also have eroded what is left in Venezuela's coffers.

Venezuela still spends billions of dollars on international cooperation, most heavily on propping up the allied communist government in Cuba.