QUITO, ECUADOR -- After centuries of virtual silence, Ecuador's large Indian population has charted a noisy collision course with the government and large landowners -- a course both sides warn could lead to violence.

The war of words is daily front-page news here and the subject of editorials, radio programs and television talk shows. The indigenous groups' new aggressiveness has stirred deep-seated fears among the upper class, which is predominantly mixed-race or white, of a violent Indian uprising or widespread killings.

Ecuador, one of the smallest and poorest countries in South America, so far has avoided the violence that has plagued neighboring Peru and Colombia in recent years. But many fear that, with its economy in decline and inflation at 50 percent and rising, Ecuador could be the next target of insurrectionist groups such as Peru's Shining Path, which has combined radical Maoism with calls for restoration of Indian supremacy.

"It is all people talk about here," said one leading academic who asked not to be identified because the issue is so controversial. "People are afraid, and I really believe things could get violent."

At the heart of the conflict is the demand of the National Confederation of Indigenous Nationalities of Ecuador that the government grant land and special sovereignty to Indians, including mineral and oil rights. The group also is demanding radical land reform under the slogan: "Not one hacienda {large landholding} left by '92," in part to protest celebrations of the 500th anniversary of the Spanish discovery of the New World.

The proposals were rejected Friday by President Rodrigo Borja, who said they would lead to the creation of a "parallel state" within Ecuador, and talks between the two sides were broken off acrimoniously.

"We have been living as Indians for 500 years," said Luis Macas, vice president of the Indian confederation, at a press conference. "Now we want to live as citizens."

Macas said Indians were not trying to create a separate state but were seeking autonomy to guarantee that their language and customs would be respected.

Estimates of the size of the Indian population range from 25 to 40 percent of Ecuador's total of 10 million, the majority of which is mestizo, or mixed-race. Most Indians are highland Quechuas, but the Indian confederation also includes other highland tribes as well as ethnic groups from the Amazon basin.

In its first real test of strength, the confederation mobilized more than 1 million people across the country on June 4 to blockade main highways, "invade" private land and occupy churches in support of its demands. The scope and coordination of the protest astounded much of the non-Indian population.

"There had been small takeovers before, but what really scared people was the fact that the Indians were able to coordinate such a huge thing," said one prominent political analyst. "The fear here is very real and very deep."

The confederation had called off a second "uprising" scheduled for earlier this month. But following the breakdown of the talks with the government, it renewed its threat to take further action.

In response, some conservative landholders have talked of arming themselves to defend their lands. There also has been talk of hiring Colombian mercenaries to protect the farms from what many believe is a plot by the radical left.

"We have the right to protect ourselves," said Ruben Espinoza, vice president of the Cattlemen's Association of the Highlands, in a radio interview. "There are no paramilitary groups in existence, but if the law is not being enforced, what are citizens supposed to do?"

The landowners say the army and police failed in their duty to break up the blockades and evict Indians who invaded farmers' land.

"In some places, the police, instead of kicking the invaders out, are peacefully coexisting with the Indians," Espinoza said. "The farms are paralyzed, crops are not being planted, and the consequences will be hunger and a food shortage."

Emotions were further inflamed last week when Espinoza and others made public a document circulating in the armed forces saying the indigenous movement was a "subversive movement" sponsored by "the so-called progressive church, overseen by foreigners and financed by money from outside the country."

Macas demanded that the government publicly repudiate the paper and said the charges were made because few believed the Indians were capable of mobilizing themselves.

"We think the time has come to be taken seriously, so Ecuadoreans realize we exist," Macas said. "That is why the first uprising was necessary, and we got attention. Otherwise, we only exist during elections, when politicians need our votes. But they never return after lying to us."

Borja's government is in a difficult position. It is unwilling to meet the Indians' demands but, because the president is a leftist, his advisers say the military and landowners do not really trust him to safeguard their interests, either. He has also warned the landowners against arming.

"The government is very aware of the efforts to organize groups and the violence that could ensue," said a diplomat. "They are doing everything they can to keep that from happening."

No one seems to have any idea how the conflict will be resolved.

"We need to get rid of the traditional paternalism of the right toward the Indians and the romanticism of the left, because both distort reality," the academic said. "Otherwise, we will have Ecuadoreans killing Ecuadoreans."