(Adds other moves against the opposition, context)
By Daniel Wallis and Esteban Israel
CARACAS, March 19 (Reuters) - Venezuelan intelligence agents arrested the opposition mayor of San Cristobal on Wednesday for "civil rebellion," accusing him of stoking violence in the city hit harder than anywhere by more than a month of unrest.
Interior Minister Miguel Rodriguez Torres, who also heads the national intelligence service Sebin, told state TV that Sebin agents detained Daniel Ceballos while 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."
A man identifying himself as an aide to the mayor said via his Twitter account, @Daniel_Ceballos, that he was arrested in Caracas. According to a post on his Facebook page earlier, Ceballos was in the capital for a meeting of opposition mayors.
San Cristobal, home to some 250,000 people in Tachira near the Colombian border, has been the focus of the most sustained fights between demonstrators barricading roads, 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.
Earlier, prosecutors said a Caracas municipal worker was killed by multiple gunshots late on Tuesday as he and others dismantled a street barrier set up by opposition demonstrators.
On Monday, the Supreme Court ordered the opposition mayors of four municipalities, including San Cristobal, to remove street barricades rigged up by protesters.
At least 31 people have died since Feb. 12 when three people were shot dead in clashes after an opposition rally in Caracas.
STUDENTS TO MARCH
The protesters are demanding socialist President Nicolas Maduro resign, while he 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 to demand Ceballos' release, in what will be the latest of daily rallies by both sides around the politically polarized country.
The move against the San Cristobal mayor comes a day after the ruling Socialist Party-dominated Congress 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 stay in the streets to keep protesting against high inflation, shortages of basic foods, and one of the worst rates of violent crime in the world.
The protesters are far fewer than those who took to the streets in 2002 to topple Chavez, albeit briefly, and opposition leaders are deeply divided over the current confrontations. (Editing by Lisa Shumaker)