SAN CRISTÓBAL, Venezuela — No one here is hiding the heavy artillery, such as it is. Students camping out on an intersection of this city, which has become a battleground between the authorities and antigovernment protesters, have a variety of homemade weapons — mortars to lob small, noisy explosives, miniature firebombs, slingshots, clubs and nasty-looking things called Miguelitos made from hoses festooned with nails.

“We’re not peaceful here,” said Andryth Niño, 19, toying with a two-and-a-half-foot-long Miguelito one night this week as she sat with companions on the curb near the students’ ragtag camp, which had been rebuilt after being flattened a few nights earlier by National Guard troops. “You can’t be peaceful when they’re always attacking you.”

Opposition political leaders and protest organizers in Caracas, the capital, have been urging demonstrators to use nonviolent means to confront the government, and most of the large marches and rallies around the country, including here, have been carried out peacefully.

Yet the appeal to nonviolence had little echo among some of the most determined protesters in this western city, where the rallies started this month and where confrontations with government troops have been most intense.