President Violeta Barrios de Chamorro called out the army on Monday to help police restore order in Managua, where government backers clashed with striking pro-Sandinista workers.
Earlier Monday, thousands of anti-government demonstrators built barricades of paving stones and lighted bonfires in the capital in defiance of a threatened police crackdown on the strike.
One person was killed and 34 others were injured in street clashes Monday. Four people have been killed in strike-related violence since Friday.
Gunshots could be heard in the capital, and an Interior Ministry spokesman said a Sandinista striker was killed Monday morning during a confrontation between strikers and supporters of Chamorro's ruling National Opposition Union at a state-owned textile plant in Managua.
Chamorro went into an emergency meeting with her Cabinet Monday night and later addressed the nation on government-run Radio Nicaragua, ordering the army to help police maintain order.
"The disorder that the Sandinista Front is promoting has not been successful," Chamorro said. "The barricades they are constructing will not stop the people from rebuilding the economy.
"Today, I ordered the army to immediately proceed, along with the national police, to maintain public order and guarantee citizens' security," Chamorro said.
Chamorro said she ordered the army, still commanded by Sandinista officers, and police to remove the strikers' barricades.
She said the troops were also ordered to turn over public buildings occupied by the leftist pro-Sandinista strikers to "civilian authorities."
The walkouts cut off electricity and water service to most of this city of about 1 million. An air traffic controllers' strike closed the airport. Mail service and operator-assisted phone calls have been suspended since last week.
The threat of violence also prevented delivery of Chamorro's pro-government newspaper, La Prensa.
The strikers, who began their walkouts last week, have called for a major wage increase and for Chamorro to drop her plans to privatize state-owned companies and return land expropriated by the leftist Sandinista government to their previous owners. They also are protesting what the unions say are massive firings by the Chamorro government. Workers also want a greater voice in setting economic policy.
Dozens of student supporters of the Sandinista strike seized a government broadcasting center in an attempt to prevent Chamorro from addressing the nation. They broadcast manifestoes for two hours urging people to join the walkout.
At about the time the students took over Radio Nicaragua and the state television network studios, the Sandinista-dominated communications workers union announced that its members were walking off the job, threatening to cut telephone and other services.
After about two hours, a student announced over Radio Nicaragua that police told them to leave and that they were doing so peacefully. They also left the state TV network studios.
The Labor Ministry warned strike leaders Monday that they could be arrested and tried for fomenting public disturbances, a charge that carries a mandatory sentence of six months' to two years' imprisonment.
Sandinista leader Daniel Ortega, who was defeated by Chamorro in an election earlier in February, urged her government to negotiate, saying in a radio interview: "This conflict cannot be solved by force. Any attempt in that direction is an invitation to chaos."
The capital was at a near-standstill as the barricades blocked some main streets. It was reminiscent of the 1979 revolution, when Sandinistas built roadblocks in their fight to overthrow dictator Anastasio Somoza.
Strike leaders claim that more than 80,000 public and private sector workers have joined the walkout.
The strikes are directed against government offices, public transportation, telephone and mail services, banks and state-run agriculture, textile and construction businesses.
A similar strike by public sector workers hit Nicaragua hard last May. Strikers won major concessions, including raises of 100%.
The government suspended talks with the strikers over the weekend, saying negotiations must deal only with labor issues, not political topics.
It declared the strike illegal, claiming it was politically motivated. The declaration allows the government to fire striking workers.
The government says tough measures are needed to rescue Nicaragua's crumbling economy, including cuts in government subsidies, higher utility rates, privatizing state enterprises and returning land confiscated under the Sandinistas.
Nicaragua's economy has been battered by nearly 10 years of war between the Sandinistas and the now-disbanded Contras and by an economic embargo by the Reagan Administration.