In a rocky gorge that bisects the Pan American highway nine miles south of this provincial capital, a silver-painted bridge lies crumpled in brown river water.

"This is the way subversive elements contribute to the progress of your nation," reads the sign painted on the bridge's foundation as a note to travelers along the potholed detour. Leftist guerrillas have been warring on Guatemala's succession of military governments for the better part of two decades.

Down the road, past a temporary bridge erected to keep traffic flowing, a band of civilians armed with carbines manned a roadblock making identity checks. Their presence underlined that although the bridge was dynamited two years ago at a high point of the guerrilla activity, the war in the scrubby hills that rise beyond it continues.

Indeed, here in the Indian highlands of northern Guatemala the guerrilla war that has simmered largely without including the impoverished Indians--about half of Guatemala's 7 million people--is showing signs of heating up after a relatively quiet period.

A week ago, in neighboring Quiche province, five Army engineers were killed when their truck ran over a claymore mine. That same week, 22 villagers in another part of the province were reported to have been killed. Accounts conflicted on whose side the victims served.

Daily reports describe kidnapings, isolated shootouts in the hills, and bodies, often burned and mutilated, found along the roadside.

Military checkpoints--or those manned by civilian defense forces under Army command--have multiplied. Leaders of some of the 23 Indian tribes--for whose hearts and minds both the Army and the guerrillas vie--report a resurgence of Army retaliations against villages suspected of harboring or supporting guerrillas.

"Our people are once again being forced to flee their villages into the mountains to save their lives," an Indian leader from a highland tribe reported, insisting his name not be used lest he be a target for government reprisals. "Again our people are being made the targets for the Army just because they live where the guerrillas are suspected of hiding."

Indian leaders and other worried Guatemalans interviewed in a week-long trip to northern Guatemala pegged the revival of the conflict in the countryside to the Aug. 8 palace coup by Defense Minister Oscar Mejia Victores against Gen. Efrain Rios Montt, the fundamentalist lay preacher who had himself come to power in an Army coup 16 months earlier.

Although Rios Montt's rule was criticized, he is widely credited with having managed to contain the guerrilla war by luring or forcing the Indians to rally to the side of the Army.

Adopting a tactic he labeled frijoles y fusiles ("beans and guns"), Rios Montt sought to isolate the guerrillas by offering the impoverished and neglected Indians food handouts and work and providing arms for them to form civil local civil defense units under Army control.

Although initially Rios Montt's policy relied more on the fusiles than frijoles, he gave the Indians a powerful voice on his advisory Council of State. These efforts isolated the guerrillas from the Indians.

Under the civil defense program, young males--often under the threat of being considered subversives themselves--joined in patrolling their districts under Army command. These units, which now include half a million Indians, provided the Army with eyes and ears in the countryside. The vast pool of men might otherwise have been lured to the side of the guerrillas.

The result was to deprive the guerrillas of even the tacit support of the Indian communities on whom they partly relied for food, intelligence and new recruits.

"Our people basically are neutral in the conflict," said a leader of the Rabinal Achi tribe who asked that his name not be used. "They basically just want to be left alone because they know if they side with the subversives they will be eliminated by the Army, or if they side with the Army they will be eliminated by the subversives."

Under Rios Montt, the tribal leader said, it became prudent to side with the government because it had the upper hand and was, for the first time in Guatemalan history, offering the possibility that the voice of the Indian majority would be heard by the Latin minority ruling in the capital.

But the Indian leaders interviewed said that since Gen. Mejia came to power in August, the situation in their mountainous homelands had changed for the worse.

Despite governmental claims that an amnesty offer had brought hundreds of guerrillas to the government side, and led 12,000 displaced Indians in the mountains to return to their villages, Indian leaders insisted their people were frightened of the Army under Gen. Mejia and were taking to the hills.

Reports that Gen. Mejia planned to dissolve the Council of State added to the disquiet.

"Things are getting worse, not better," said a young leader of the Mam tribe from the central highlands. "We thought that after centuries we were about to be treated as human beings, not animals . . . . If we are now not going to be given that, we will go to blood and many more will die. We don't want that, but the government once again seems to be holding that out as our only alternative."

Mejia's apparent switch in tactics toward the Indians is seen by analysts in the capital as a consequence of the return to power of the old guard military that in the past viewed the Indians as second-class citizens providing cheap labor for the coffee and sugar cane barons with whom the Army allied.

Rios Montt's coup was staged by younger officers rebelling at the corruption and lack of social conscience of their elder officers. It was these young officers who supported Rios Montt's efforts to bring the Indians to the side of the government.

Analysts say, however, that their influence on policy ended when Mejia took over and reasserted the authority of the old military hierarchy.

"Instead of change," said a worried social democratic politician in the capital, "we have moved backwards. I am truly afraid now that there will be only more bloodshed and no progress."

[In Guatemala City, The Associated Press reported Wednesday, the Army said soldiers overran three guerrilla camps in the northwest Indian area, killing 25 rebels and confiscating weapons, medicine and propaganda.]