Guerrillas staged a destructive raid here recently, terrorizing residents and leaving the town in a shambles.

Or did they?

The conflict wracking this country often presents many more questions than answers. In a climate of violence, truth is elusive. The attack on this dusty fishing town illustrates the uncertainties Salvadorans have come to accept as part of their daily lives.

This much is known: On the evening of June 27, a large band of raiders stormed La Union. They rampaged through the streets, destroyed utility lines and severely damaged many buildings. While the 24,000 residents cowered under beds and behind locked doors, the attackers spent a leisurely 36 hours shooting up the town.

As the shooting continued, Army commanders in San Salvador called the situation "very serious" -- a rare admission from the military, which normally dismisses guerrilla attacks as minor and ineffective. Military spokesmen implied that the rebels had arrived here by boat from Nicaragua, just a few miles away across the Gulf of Fonseca.

Three U.S. nval advisers were stationed near La Union at the time of the raid, but the U.S. Embassy told reporters there was no need to evacuate them.

Then, a week later, the insurgent Farabundo Marti National Liberation Front issued an extraordinary statement denying that its forces had launched any attack on La Union. The seaborne assault, according to the front, was "a maneuver of the governing junta and the armed forces to create alarm by saying the attack was the result of aninvasion of Cubans and Nicaraguans."

The public will probably never know what really happenend here. But the military version contains so many anomalies that many Salvadorans have come to believe the Army staged the attack on La Union to portray its guerrilla enemy as foreign-backed and very strong. On that basis, the ruling junta has appealed to the United States for increased military aid, which Ambassador Deane Hinton said last month would be forthcoming.

La Union is not a likely target for a guerrilla attack. It is located on a eninsula that can easily be sealed off by soldiers. There are three airfields within a few miles, so reinforcements could easily have been flown airfields within a few miles, so reinforcements could easily have been flown in if they were needed.

"Crushing an attack on La Union would be well within the capability of the Army," said one Salvadoran military specialist. "The 3d Brigade is 45 minutes away in San Miguel, and there is a Ranger battalion just north of there at San Francisco Gotera. They have all the jeeps, trucks and helicopters they wuld need to move reinforcements in quickly."

But according to residents, the raiders were in no hurry to flee. Though rebel attacks on large towns like this one are usually over within an hour or two, the men who attacked La Union spent the better part of a weekend on their mission, apparently not fearing resistance even though there are 120 soldiers quartered here and many more nearby.

The acting Army commander here said that many of the soldiers were called out to fight the attackers. However, the local priest, who was summoned to the barracks during the incident, said he saw most of the soldiers going about their normal business in and around the base.

The military barracks and the city hall were left almost untouched by the attackers. The most heavily damaged building in town is the Roman Catholic Church, an unlikely target for guerrillas, who generally view the church as a defender of human rights.

Also destroyed was the office of Caritas, the Catholic relief agency that feeds 1,200 needy children here every week. Caritas has been strongly criticized by the Army as being linked to leftist groups, an allegation it has denied.

The priest, who asked that his name not be used, took a visitor through the vandalized church, which is now closed and guarded by armed soldiers. Statues of saints are pockmarked by bullet holes, the French-made, stained-glass windows are full of holes, and the floor is littered with plaster and spent cartridges.

"It was very sad to see a house of God destroyed in this way," said the priest. "I cannot understand who would do this or why."

Perhaps strangest of all, not a single body was left behind by the attackers. No soldiers were killed, either.

"The subversives have an excellent system for evacuating their dead," explained the local military commander, Maj. Roberto Segovia.

At the Red Cross office on the outskirts of town, Luis Ramon Molina, the director, said he never say the attackers because he had been barricaded inside his home while "heavy gunfights" were going on outside.

"Two civilians were killed in crossfire and we treated four soldiers for light wounds, but we know of no deaths among the combatants," he told an interviewer. w

This raid marked the second time in six months that La Union has been in the news. On Jan. 14, U.S. Ambassador Robert White said that 100 Nicaraguans and other foreigners had landed on a beach near here. But the attack also proved suspicious, and White later retracted the accusation, which was based on information given to him by the defense minister, Col. Jose Guillermo Garcia.

In Washington recently, White, now retired from the Foreign Service, noted similarities between that "invasion," which apparently never happened, and the more recent raid. Asked if the Salvadoran Army might have attacked the town itself to create a sense of urgency as it presses for increased U.S. aid, he replied: "Based on the available evidence, that's the only conclusion I can come to."

In La Union, an elderly man sitting under a palm trea in a vain effort to escape the blistering heat had a less definitive explanation.

"What I can tell you is that whoever did this has no respect for decency," he said. "Why don't they leave us alone?"