CARACAS (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 Mr 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, Mr 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.

Mr 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 took down 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.

The protesters are demanding socialist President Nicolas Maduro resign, while he says his foes want to create chaos and a coup.

Students said they planned to march in the capital on Thursday to call for Mr Ceballos' release, in what will be the latest of daily rallies by both sides around the politically polarized country.