MANAGUA, Nicaragua — A rock-throwing Sandinista gang broke up an opposition rally here Friday, sharpening political tensions in Nicaragua three days after the suspension of a wartime state of emergency.
Later, tens of thousands of people packed Managua's Revolution Plaza and shouted "People's power!" in a government-led demonstration against those on the political right whom they called traitors.
The morning assault by about 30 partisans of the ruling Sandinista National Liberation Front sent glass from a shattered door and windows flying into a crowded auditorium, cutting two of the 300 or more people attending the rally inside. The building is headquarters of the Nicaraguan Democratic Coordinate, the country's main conservative coalition.
Three policemen intervened without force to stop the rock throwing after about two minutes and made no arrests.
It was the boldest and most politically significant assault by the Sandinista gangs, known as turbas , since they wrecked opposition rallies during the 1984 election campaign.
"The Sandinista front has lifted the state of emergency but it is imposing a state of terror in Nicaragua," charged Agustin Jarquin, secretary general of the Social Christian Party, as he nursed a gash on his neck that bloodied the back of his shirt.
The attack was the latest in a quick succession of actions against dissent that appear to undermine the government's effort to convince the U.S. Congress of its democratic intentions.
Faced with a potentially close congressional vote next month on the Reagan Administration's request for new aid to the Contras, Nicaraguan President Daniel Ortega agreed at a Central American summit meeting last Saturday to lift emergency laws that allowed the police to ban dissident gatherings and hold prisoners indefinitely without charge.
After Ortega had left last Friday for the summit in San Jose, Costa Rica, the police arrested seven leaders of the Democratic Coordinate. Then on Tuesday, as emergency rule formally lapsed, five more leaders of the conservative coalition were taken into custody.
Held for up to 36 hours, all 12 politicians were interrogated about a meeting that they had attended in Guatemala with two men identified as U.S. officials and leaders of the anti-Sandinista guerrillas.
The arrests were carried out by the Interior Ministry, the agency in charge of organizing Sandinista gangs in the past. Along with Friday's attack, the detentions fed speculation that Interior Minister Tomas Borge was showing discomfort with the new curbs on his police powers.
'Acting on His Own'
"I think Borge is acting on his own," a European diplomat said. "But it's not just Borge versus Ortega. The Sandinistas have a big problem within their cadres and within the military" over concessions made by the president.
At the summit, Ortega also agreed, in compliance with a regional peace accord, to hold face-to-face cease-fire talks with rebel negotiators and to free 3,300 political prisoners if a country outside Central America will accept them as refugees.
Callers to Sandinista radio stations this week have protested Ortega's concessions as too broad, and editorials in the party newspaper, Barricada, have warned the opposition not to take advantage of the new freedoms to defy Sandinista power.
Anticipating mob action to enforce that warning, Barricada said Tuesday that the "legal defenses that have contributed to stop the imperialist policy inside our country will now be substituted by other forms of struggle that are not unknown to the masses."
Attackers Had Loitered
Several witnesses said the group that attacked Friday's opposition rally arrived and left in three pickup trucks and a minibus with no license plates. They loitered about 30 feet from the auditorium under a Sandinista banner that read: "Anyone Who Doesn't Understand Patriotism, Get Out!"
The rock throwing started when five men left the auditorium, in Managua's Ciudad Jardin commercial district, and tried to scale a lamppost to haul down the banner.
"Glass was flying everywhere but I thought it was bullets," said Rosa Cruz Sovalbarro, an elderly woman who was cut on the left ear as she ducked behind a post inside the building.
Bayardo Arce, one of nine members of the governing Sandinista directorate, said later that the attack was provoked by the opposition "to give arguments to Reagan" for congressional approval of more Contra aid.
Warning to Militants
Speaking at the government rally, Arce warned Sandinista militants to obey the law and "avoid falling into provocation." But he also called them to "a state of alert to defend the revolution" and added: "We will not stand by like fools. If the right takes to the streets, the Sandinistas will take to the streets as well."
The opposition rally was organized by the Mothers of January 22, a group of political prisoners' relatives, to demand their release. When the rocks flew, many of the women, frightened and in tears, took refuge in a storeroom behind the auditorium.