Venezuelan intelligence agents arrested an opposition mayor on Wednesday who was accused of stoking violent protests, and another was jailed for 10 months in the latest moves against rivals of President Nicolas Maduro.

The steps follow court orders instructing mayors of opposition-run municipalities to dismantle street barricades set up by demonstrators, which have become flashpoints for more than a month of unrest that has killed 31 people.

Daniel Ceballos, mayor of the hard-hit city of San Cristobal near the Colombian border, was detained by the national intelligence service Sebin and accused of "civil rebellion".

Interior Minister Miguel Rodriguez Torres, who also heads Sebin, told state TV that Ceballos was detained by agents acting on an order from a court in western Tachira state.

"This is an act of justice for a mayor who not only failed to meet his obligations under the law, but also facilitated and supported all the irrational violence in this city," he said.

"In the coming hours he will be presented before the corresponding tribunals to begin the judgment process."

An aide to Ceballos said he was arrested in Caracas, where he had been attending a meeting of opposition mayors.

San Cristobal, home to some 250,000 people, has been the focus of the most sustained fights between hooded demonstrators barricading roads, armed pro-government radicals, and the security forces.

Torres said a member of the National Guard was shot dead in the city on Wednesday during what he called "vandalistic acts" by protesters targeting a national armed forces university.

Later on Wednesday, the Supreme Court jailed another opposition mayor, Enzo Scarano of San Diego in central Carabobo state, for 10 months and 15 days for failing to comply with a previous order to take down barricades there.

In a statement, the court said Scarano would be stopped from exercising his functions as mayor.

"All our solidarity with Enzo Scarano before this indescribable aggression," tweeted Ramon Muchacho, mayor of the staunchly pro-opposition Chacao municipality in eastern Caracas, which has been the site of near-nightly street clashes.

Students to march

At least 31 people have died since Feb 12 when three people were shot dead in clashes after an opposition rally in Caracas.

Prosecutors said a municipal worker was killed in the capital by multiple gunshots late on Tuesday as he and others dismantled a street barrier set up by opposition demonstrators.

The protesters are demanding Maduro resign, while the socialist president says his foes want to create chaos and trigger a coup, like the one 12 years ago that briefly ousted his predecessor and mentor, the late Hugo Chavez.

Pro-opposition students said they planned to march in the capital on Thursday, in what will be the latest of daily rallies by both sides around the politically polarized country.

The move against the two mayors comes a day after Congress - dominated by the ruling Socialist Party - voted to ask the state prosecutor to investigate an opposition deputy for crimes including treason in relation to the protests.

Maria Corina Machado, a 46-year-old engineer, has been one of the most visible leaders of the demonstrations.

The move by "Chavista" legislators, which seeks eventually to strip her of her parliamentary immunity, followed the arrest a month ago of hardline opposition leader Leopoldo Lopez.

Along with Machado, Lopez launched a national movement at the start of the year under the banner "The Exit", meaning an end to 15 years of socialist rule. It has seen peaceful marches as well as melees between hooded demonstrators and riot police.

Lopez handed himself in to face charges of fomenting the unrest. A senior colleague from his Popular Will party is on the run after being accused in connection with the violence.

They have called on supporters to continue their street protests against the Maduro government. Protesters are far fewer than those who took to the streets in 2002 to topple Chavez and opposition leaders are deeply divided over the current confrontations.