San Pedro Arenales, El Salvador — There is tension in the air. The residents of San Pedro Arenales have heard that a 350-man Salvadorean Army Hunter Battalion may be coming this morning. They are particularly apprehensive because several dozen guerrillas are in the hills overlooking the town. Their homes and families could be caught in the middle of a battle.
Despite these worries, a cluster of men and women stand around a local oxcart builder who chips away at a piece of wood. The rolling green hills and rhythmic sound of the wordworking provide a false serenity.
Several people peer nervously up the road and then glance toward the ridges above them. There has been no traffic on the road for two days.
''There was a fight yesterday in Las Marias,'' one woman says, ''and last night a column of about 200 guerrillas came into the town before taking up positions in the hills. We are in danger if the Army comes because we will be caught in the middle.''
The rebels operate with impunity in most of Usulutan Province. They are periodically subjected to Army sweeps and Air Force bombing. Residents say bombing has taken place outside the village.
''Every time the Army moves in to reoccupy the town or hunt down the guerrillas, a few civilians get killed in the cross fire,'' another resident says.
Abruptly, a young woman enters the small circle of villagers and says quietly , ''The soldiers are coming.''
The message is received in silence. Several residents turn and look nervously toward the underbrush where the woman spotted the patrol. One mother lifts here two small children up in her arms and disappears down a dirt path over an embankment.
'' I'm not afraid,'' a teen-age girl says, her voice on edge, ''I've got my identification card.''
''Get in the house,'' the oxcart builder says tersely to his two small children. The two children obey, only to come outside a few moments later.
''Get in the house,'' he says, his voice filled with tension. He stomps his feet for effect and again the two children disappear into the dirt-floor hut.
When the oxcart maker's small girl peers out from the doorway, she is again sharply rebuked by her father, who is close to tears.
''There is always the possibility of a mistake,'' he says, ''of the soldiers thinking we are guerrillas or the guerrillas setting up ambush near the town. Then we might be killed.''
Most of the townspeople have taken refuge in their homes. They were careful not to walk quickly or make rapid movements and those who remain outside stand away from the houses in plain view of the road where the patrol was spotted.
In the distance, across a meadow and small brook, two soldiers are visible in green combat fatigues. One of them studies the knot of civilians that remain near the oxcartmaker. The civilians do not return his gaze or acknowledge his presence.
''The soldiers are coming down the path,'' a woman says in a hoarse whisper as she walks by us. Everyone glances involuntarily toward the dirt path.
Several soldiers move down from the road. A column of troops appears with ammunition belts across their chests.
The civilians nod to troops, who also appear nervous. The soldiers frequently glance up to the ridges above the town.
At this moment the plight of both the soldiers and civilians becomes apparent. The war here is fought largely by ambushes and most of the ambushes are set up by the guerrillas against Army troops.
Troops who move into a zone where guerrillas are located must be prepared for an attack at any moment.
Residents must swallow their fear and keep up a semblance of normality. If they alter their behavior, the soldiers become more nervous and the level of danger increases.
About 40 soldiers converge from three directions on the town center. They ask to see the residents' identification cards.
There is little communication between the villagers and soldiers. As the troops stand in the central plaza, many drinking a red soft drink out of small plastic bags, a mortar shell explodes outside the village followed closely by another. There is a brief round of automatic gunfire.
On the dirt road outside of town the lieutenant of the battalion crouches to speak to his rear guard on the radio.
''I can't speak to you now,'' he tells me, ''we have problems. We are working and now there are problems.''
Again the sound of automatic gunfire comes from the hills. The soldiers near the lieutenant stand close to the edge of the road, which is sheltered by an overhang.
The lieutenant informs his rear guard that my car will pass.
''Go now,'' he says, ''it is safe to go now, but in a few minutes I will not be able to say if it is safe or not.''