A rude cross carved on a tree trunk marks one of the graves where peasants said today they had buried at least 48 people killed by the armed forces. Nearby is another tree, its gnarled roots matted in blood and human hair. Dogs have dug up at least one body.

Army spokesmen vehemently denied that any massacre occurred here and said it is investigating the case. In Barrios, an isolated collection of huts about 100 miles east of the capital, few people are left to question.

One of them is Pablo Flores, 34, a peasant, who said his daughter, niece and sister-in-law were among the people killed Sunday morning when about 50 soldiers entered the area in three trucks. He said he and his wife had been with relatives in San Pedro, a few miles down the rutted dirt road, when they saw the trucks go by about 6 a.m.

"Soon there was a lot of gunfire," he said, "and later a woman came out. She was screaming, she was crazy from it. Everybody was dead."

Barrios lies in the war-torn province of Morazan where El Salvador's guerrilla war has taken hundreds of lives. Cab drivers talk easily about the evacuation of other towns further north attacked by guerrillas during the weekend, and about the people who fled from Barrios after the Army came through. "Every night there is shooting," one said. "Who knows who it is?"

It is always clear in these cases that something has happened, that some people have died violent deaths and that many peasants in the area are very frightened. There is never any way to tell for sure how many people are dead or who killed them. A spokesman for the U.S. Embassy said it tries to look into all such incidents but can rarely make any definite findings.

It is routine in such cases for the guerrilla left to charge that the Army has slaughtered innocent people, trying to frighten them out of collaborating with the leftists, and routine for the armed forces to countercharge either that the guerrillas, dressed as soldiers, did it themselves or that the dead are guerrillas killed in battles elsewhere and brought to a site just to be produced for gullible journalists.

What is clear in Barrios is that many simple people say in very similar words that men dressed as Army soldiers killed at least 48 of their neighbors.

The first reports of major trouble here came in an anonymous phone call to a San Salvador radio station Monday morning. The story was one of the few in recent days that did not concern the struggle of politicians to form a government in the relative peace of the capital, one of the few stories to remind Salvadorans that the March 28 elections may change the government but they have not yet stopped the war that goes on in the countryside.

At the foot of the cross on the tree, across the shallow Seco River from the huts of Barrios, is a dug-up area about 20 feet square, where Flores said about 25 people are buried. Dogs have dug up and scattered some bones, and one skull with gleaming, gold-studded teeth is visible. It looks too clean to be newly dead, but the dogs are always hungry.

A few feet away is the bloodstained tree, its roots sticky with blood where bullets have torn away the bark. A few shell casings, not many, share the dirt with a campesino's straw hat, a woman's plastic sandal, a few bits of clothing.

Hector Bialta Osorio came back today to pick up some of the clothes and other remnants of a life that he left behind when he fled Sunday morning. "When the shooting started I saw the soldiers making everyone lie down like this," he said, putting his face to the ground and his hands behind his head. He said the soldiers raped many of the women. "Then I ran down the back way across the field, and then I heard the shooting."

Serbando Hernandez, 45, a weatherbeaten farmer, went in from San Pedro with some other men that afternoon to see what had happened. "They had killed women pregnant out to here," he said. "There were little children lying on their backs like this," he said, throwing his head back. He made a cutting motion across his throat, and smiled the twisted, involuntary smile of a man about to cry. He blinked rapidly and shook his head. "It was horrible, horrible," he said.

Hernandez said he walked past the bodies to find the body of his young cousin, and he buried it with some others. He said there are four gravesites in all, one across the stream and three in the village. The youth's mother, Santos Benitez, 50, said she was in her house when the noise began about 7 a.m. "I hid under the bed with my children, and when the shooting stopped we ran through the fields. I could never go back," she said.

The men who did the shooting wore green uniforms and helmets, she said, and carried rifles and machetes. A little while later there was more shooting from another direction, apparently a guerrilla attack on the soldiers, she said. Other peasants in houses along the road to Barrios said Red Cross vehicles had gone into the area and come out bearing wounded soldiers late Sunday morning.

Several people talked about Hilario Benitez, 65, who had survived the Sunday attack that took the lives of his wife, his stepdaughter and her three children, only to die Monday when a plane flying low over the village lobbed several grenades into the area. They said he bled to death of a leg wound.

Nearly all the villagers said they had walked several miles to town to vote in the March 28 elections. "The officials said if we didn't they would come and drag us out at night," said Pablo Flores. "If we didn't we expected to die," said Santos Benitez. Nevertheless, she said, she stayed home to take care of the children. "They're all the same, the politicians," she said.

Serbando Hernandez does not know what to do now. He cannot go back to Barrios because he is afraid, he said. "We don't know anything about anything anymore," he said. "We may die tomorrow. Only God disposes."