New violence broke out here today as President Augusto Pinochet, marking a decade of rule, promised Chileans that his military government would reactivate the economy and move toward democracy. Two persons were reported killed.

In a two-hour address delivered in a government office building and broadcast on national television, Pinochet defended his long rule as having guaranteed "peace and liberty" for Chile in what he called "the worst defeat for communism."

As the official government ceremonies began this morning, however, street violence resumed for a fourth straight day when government authorities sought to force several thousand workers in a government employment program to attend a demonstration arranged for Pinochet in the downtown area.

Residents told reporters that part of a crowd of 5,000 gathered by authorities on a soccer field in the community of Pudahuel chanted an antigovernment slogan and were fired on by men in an unmarked car. Police later arrived to break up the crowd with tear gas. The government news agency ORBE said two persons were shot to death, and as many as 11 persons were reportedly injured in the episode.

The deaths raised to 15 the number of persons reported killed in political violence since Wednesday, including one policeman shot while guarding a judge's house Friday and five alleged members of the extremist Revolutionary Left Movement. The other fatalities have been civilians shot by police or unidentified civilian groups during nightly protests in poor neighborhoods.

Tonight, protests continued in scattered parts of southern and eastern Santiago where residents built barricades and marched through streets chanting antigovernment slogans. In many areas, police appeared to avoid confrontations, remaining on the outskirts of barricaded neighborhoods. However, incidents were reported near Santiago's national stadium after a soccer match. No serious injuries were reported.

About 1,000 persons gathered in the coastal city of Vina del Mar today and marched from the grave of Salvador Allende, the Socialist president who died in the Sept. 11, 1973, military coup that brought Pinochet to power. The peaceful six-mile march included activists of leftist Chilean parties as well as centrist Christian Democrats who were Allende's political opponents, according to reports from that city.

The gathering at Allende's grave was the only major demonstration called by the opposition, however, and politicians said today that continuing protests in Santiago neighborhoods were being organized on the local level, perhaps with the encouragement of the outlawed Chilean Communist Party.

Pinochet, who was greeted only by a relatively small crowd downtown, attacked the protests as "called by opposition groups that have made a show of their scandalous rhetoric and their recognized demagoguery."

He maintained that "we have never denied our opponents the right to express their ideas and even less have we pretended that all our countrymen unconditionally adhere to our propositions."

Despite the attack on opponents and a familiar critique of Allende's government, Pinochet struck a moderate tone, neither threatening new repressive measures nor announcing substantial initiatives.

The general, 67, said that state workers would receive a 15 percent raise in January and outlined several minor measures to lower taxes of small mining and factory owners.

Pinochet predicted that his government would lead the country to an economic growth rate of 5 percent in 1984. However, he made no statement to satisfy government leaders who have advocated a major shift toward economic stimulation.

In political policy, Pinochet reiterated government pledges to relax restrictions on political activity, but offered no details and appeared less committed to measures previously announced by Interior Minister Sergio Onofre Jarpa.

Jarpa has promised a plebiscite to modify the constitution so that congressional elections will be held no later than 1987 rather than the scheduled date of 1990.

Pinochet, who is scheduled to rule until at least 1989, said only that "the government will consider the possible holding of a plebiscite . . . over eventual constitutional modification."

Pinochet made no mention of demands by the opposition Democratic Alliance for a firm agenda for talks with the government. Instead, he focused on defending his 10 years in government, reciting at length accomplishments ranging from the number of houses built to the number of trees planted and kindergarten lunches served.

"The armed forces and the security forces saved Chile from totalitarian tyranny," Pinochet declared.

Many of the commentaries marking the anniversary of the military coup were critical, even in progovernment newspapers. The conservative daily El Mercurio editorialized that "the government's indecisiveness in timely addressing the accusations . . . of violations of human rights will hang over it always as a historical shadow."