Lawyers for the jailed opposition mayor of Caracas said Saturday they would ask a judge to dismiss conspiracy charges against him, calling accusations that he participated in a plot to overthrow Venezuela's socialist government "totally unfounded."

Mayor Antonio Ledezma was arrested at his office Thursday by an armed commando unit dressed in camouflage. The detention set off a wave of demonstrations in middle-class Caracas neighborhoods with people denouncing what they called the mayor's "kidnapping."

Ledezma is being held at the Ramo Verde military prison, the same facility where fellow opposition leader Leopoldo Lopez and the former mayor of San Cristobal, Daniel Ceballos, are being held.

The attorney general's office has said that Ledezma was arrested on the order of a local court for "conspiring to organize and carry out violent acts against the government." Conspiracy is punishable by 8 to 16 years in jail.

On Saturday, Ledezma's lawyer, Omar Estacio, said he would fight the charges against his client.

"We are going to appeal the judge's decision," Estacio told The Associated Press. "The charges are totally unfounded, and this doesn't even take into account that he was detained without an arrest order from any authority being presented."

The arrest of the 59-year-old mayor, one of President Nicolas Maduro's fiercest critics, comes as the government struggles to avert a crisis made worse by a recent tumble in oil prices. The president's approval rating was hovering around 22 percent in January, the lowest in 16 years of socialist rule, as Venezuelans are forced to cope with widespread shortages and runaway inflation.

Maduro has taken to the airwaves to rail against his opponents, accusing them of conspiring with the United States to sabotage the oil-dependent economy and carry out a coup.

The government's case against Ledezma appeared to stem from a public letter he wrote with two other hardliners calling for a transitional government. Maduro said the letter, published in an anti-government newspaper, was the green light for a secretly hatched putsch with U.S. Embassy involvement.

The U.S. called the accusations "baseless and false."