Grieving families in this low-income suburb of San Salvador buried their dead today -- 30 bodies of men, women and teen-agers shot early yesterday morning by government troops and left strewn along a dirt road.

"We were eight living together in the house," the brother of one of the victims said. "Four men and four women. The troops came and lined us up against the wall and asked for our identity cards. My brother didn't have his card, he had lost it. They took him away for interrogation, they said. We found him dead yesterday morning."

No one in this country disputes that it is embroiled in a brutal war in which the two opposing armies -- leftist guerrillas and the troops of a civilian-military coalition government -- regularly, viciously confront and kill each other.

What is disputed, however, is who is responsible for the deaths of nonconbatant civilians who, most agree, comprise the majority of the 15,000 lives lost in political violence here over the past 18 months. The Salvadoran government and its backers in Washington maintain that most of those who are not killed in direct combat are murdered by extremists -- rampaging guerrillas or right-wing rogues both in and outside of the armed forces.

But many observers in El Salvador -- including Western diplomats and civilians outside the government -- say that many, perhaps most of the noncombatant deaths can be attributed to military operations similar to that conducted early Tuesday morning in Soyopango. It is this kind of officially tolerated, if not condoned, violence, they argue, that indicates that a military solution to the Saladoran conflict will never provide a lasting peace or gain the government the support of the Salvadoran people.

Over and over again, in private conversations with peasants in urban slums and rural agricultural cooperatives, similar stories are told. Sometimes it begins with a brief shootout in the darkened, curfew-deserted street, sometimes not. House-to-house searches are conducted, often by men in uniform, often led by one man, sometimes masked, who points out those to be taken away.

A few miles away from here is another working class suburb, called Ciudad Delgado. There, more than one-third of the houses are empty and those who remain say that their neighbors fled from similar house-to-house searches by the military. Fifteen miles away is a refugee camp called La Bermuda. Even there, there is no safety, and residents last week told of 20 people being led away by soldiers, never to return.

In rural agricultural cooperatives, the centerpieces of government programs to win the support of El Salvador's peasants, hundreds of peasant leaders have been executed. Occasionally, workers will accuse the leftists who travel in guerrilla bands through the countryside. Most often, they accuse the government security forces.

Privately, some Western diplomats concede that perhaps half of those murdered -- often killed on the word of a single informant -- probably had little or nothing to do with the guerrillas.

"The troops," said one mourner at today's funeral in Soyopango, "go through our neighborhood often and take people away."

The U.S. Embassy here, which administers the Reagan administration's new $25 million military assistance program, reportedly is putting heavy pressure on the government to stem official terrorism.

"Progress has been made" in stopping right-wing violence, Col. Eldon Cummings, the man who has been in charge of the 56 U.S. military advisers here told reporters Saturday. "I have seen the [disciplinary books] and they have disciplined people. I have also provided [the military] with my recommendations, or criticisms, if you will, of certain actions.

"But it is not simple," Cummings added. "You can't change 50 years of the normal way of doing things overnight. But I think it is changing."

A leading member of the Christian Democratic Party, the only political party sharing governmental power with the military, disputed Cummings' assessment of the level of change, complaining that, if anything, violence has gotten much worse in the last 30 days since the military began a counteroffensive against the guerrillas.

The Christian Democrats hold government security forces, or right-wing paramilitary organizations, responsible for the murders of more than 40 Christian Democratic mayors and scores of party leaders and workers.

Some U.S. officials here insist that the violence by the right is committed by lower-level extremists in the security forces or by ORDEN, a right-wing paramilitary force, originally sponsored by the government but officially disbanded 18 months ago. Many peasants insist it still operates throughout the country.

Some Salvadorans question whether the high command could stop the rightist violence without risking a coup from hard-line military officers.

One businessman, who said he had received death threats from the right as well as the left, scoffed at the suggestion that the government could not stop the random killing.

"Are you kidding?" he asked rhetorically. "ORDEN is the government."

What was different about the Soyopango shootings was that the government publicly acknowledged that members of the security forces had been involved. Official spokesmen said that the residents were killed in a shootout between government forces and leftist guerrillas. They said the shooting began after midnight when a government patrol was attacked. Although one official initially said that four soldiers had been killed, another later said government casualties had consisted of two wounded soldiers.

Asked about the incident as he left a luncheon at the Camino Real hotel today, Defense Minister Col. Jose Guillermo Garcia referred reporters to the chief of police. U.S. Charge d'Affaires Frederic Chapin, leaving the same luncheon, said he had no comment.

Families of victims in Monte Car melo, a Soyopango neighborhood where most of the dead had lived, said uniformed soldiers conducted a house-to-house search, guided by a man in a mask.Some were shot there, although all the bodies were dumped in San Carlos.

Witnesses along the San Carlos street where the dead were found said that many of the bodies were dressed.

The grieving families at today's burial showed little interest in whether mainline government forces, or supposed military renegades, were responsible for the killings. Asked what she and her neighbors thought of the government, one young woman, a co-worker of one of the victims said: "We don't discuss that."