By LARRY ROHTER
 
UIRUMUTA, Brazil - According to official maps, this remote stretch of the Amazon is an Indian reservation, set aside as the homeland of a half dozen tribes. Theoretically, that makes it off-limits to uninvited visitors. Yet white settlers have ignored the billboards that proclaim this cluster of villages to be "protected land" and have built an airstrip, a fancy technical school, a town hall and stores, all protected by a new military base.

Farther south, sprawling rice farms divert water from streams where Indians fish and bathe, and clandestine gold and diamond mines are flourishing. All over the 1,000-square-mile Raposa Serra do Sol Indigenous Reservation, white encroachment has been accelerating and becoming bolder.

Now, the newcomers to the land, which borders Venezuela and Guyana and includes Monte Roraima, the 9,218-foot peak that inspired Sir Arthur Conan Doyle's novel "The Lost World," are using the judicial system to try to evict the Indians from parts of the reservation. Seizing advantage of bureaucratic lassitude and loopholes in law, these people, led by powerful rice growers and ranchers, have persuaded sympathetic judges to order Indians to leave land that tribal peoples say they have occupied for generations.

"We were here before the Brazilian state was even formed," protested Secundino Raposa, 61, a resident of a Macuxi Indian village called Javari. "Our grandparents raised our parents here. When I was a child, we would hunt here in December and there were no whites around at all. The whites only arrived here yesterday. So how can they say this land is theirs?"

The confrontation provides the first major test of President Luiz Inácio Lula da Silva's policy toward Brazil's indigenous peoples, watched closely by Indian advocates in and out of Brazil. So far, these advocates say, Mr. da Silva has preferred to court the Indians' adversaries rather than live up to longstanding promises to tribal groups and to enforce laws already on the books.

Creating an Indian reservation in Brazil is a complicated procedure that can easily be prolonged for a decade or more. In the case of Raposa Serra do Sol, a formal demarcation of the territory to be set aside for the Indians was reached in 1998. When Mr. da Silva took office on Jan. 1, 2003, a proclamation formally certifying the registry of the reservation, the final step in the long process, was on his desk, lacking only a signature.

But Mr. da Silva, leader of the Workers Party and Brazil's first elected left-wing president, took no action during his first year in office, other than to reaffirm his support for the Indian cause. Since January, sensing vacillation in Brasília, white landowners have filed one suit after another in their campaign to block the formal registry of the reserve.

Indian leaders say they feel betrayed. They recall that Mr. da Silva visited here more than a decade ago, expressed support for their plight and promised that if he ever got into power, he would grant their demand.

"Since Lula came into office, things have only gotten worse for us," said Jacir Jose de Souza, a Macuxi Indian chief who is also director of the Roraima Indigenous Council. "He's deceitful, very unreliable. He's worse than the last government because he says one thing and does another."

The presidential press office declined to discuss the controversy, referring a reporter's request for comment to the Ministry of Justice. Speaking on condition that she not be identified by name, a spokeswoman said the government remained committed to registering the reservation and compensating white landowners for the properties they would have to relinquish, but is treading carefully because it wants to avoid bloodshed.

But friends of the Indians consider the government's lethargic approach to be deliberate. The estimated 15,000 Indians living at Raposa Serra do Sol, they say, have most likely become victims of old-fashioned backroom political deal making.

"The reservation is unfortunately being used as a bargaining chip for local and national interests," said Saulo Ferreira of the Indigenous Missionary Council, an advocacy group. "The real reasons for the delay are political, not judicial. Instead of immediately issuing the approval, as it could easily have done, the government has been negotiating for the support of the Roraima congressional delegation, and the Indians have ended up being used."

After Mr. da Silva came to power, the governor of Roraima, Flamarion Portela, announced he was joining Mr. da Silva's Workers Party. Since he controlled much of the state's delegation and opposed establishment of the Indian reserve, there was much speculation here and in Brasília that a deal had been struck: his support in return for postponing certification of the reservation.

Mr. Portela was impeached in August in a scandal involving the generation of thousands of no-show jobs that cost the state payroll millions of dollars. But Mr. da Silva's government, still trying to stitch together a majority in both houses of Congress, continues to pursue the support of Roraima's three senators, all of whom oppose the reservation.

Lucio Flavio Pinto, editor of Amazon Agenda, a newsletter, cited an additional factor in Mr. da Silva's turnabout. As leftists, he said, the president and his party have in the past been viewed with suspicion by the armed forces, who also have never liked the idea of an Indian reservation straddling a sensitive border area.

"Lula's real problem is the military, who because of deep budget cuts have been deprived of raises and new equipment," Mr. Pinto said. "But the armed forces also have national security concerns that he can more easily address. They are worried about the balkanization of the Amazon, the creation of a separate state or 'liberated area' under foreign control."

Indian leaders contrast that nationalistic rhetoric with the reality of what they describe as a flourishing black market in gasoline from Venezuela, where gasoline costs 20 cents a gallon, less than one-tenth of its price here. In addition, there are ample indications that marijuana, gold and diamonds are being smuggled across the border to Guyana and enriching local interests.

"We're enforcing ourselves the laws on the books that the government does nothing to enforce," complained Dejacir Melchior da Silva, the leader of Agua Branca, a community at the border here. "We are tired of waiting for the federal police or the soldiers to act. There are a lot of things on paper, but no one bothers to make it work."

In less than a decade several small Indian villages have been surrounded by an army garrison and a rapidly growing white squatter settlement that recently has been given the status of a municipality. Indian residents complain that soldiers harass young women, smuggle liquor into what is supposed to be an alcohol-free zone, and barge into their homes without permission.

"We want that base out of here," said Eusébio de Souza Oliveira, who lives in one of the Indian villages. "They built it so close to us that we can't hunt and fish anymore, and the soldiers have come to knock down the fences we put up to protect our animals. It's very bad for us."

Other powerful local political and economic interests have not hesitated to use violence to express their opposition to the reservation. Since Mr. da Silva came into office, they have blocked roads and occupied government offices. Mércio Pereira Gomes, president of the National Indian Foundation, the government agency in charge of indigenous affairs, describes the activity as "a sort of local rebellion, one fracas after another."

He added, "tempers are flaring and the political situation has been exacerbated."

Another group of business executives and politicians, including some from the ruling party, have said they are willing to allow formation of a reserve, provided it is not contiguous. But Indian leaders, anthropologists and human rights groups unanimously oppose a series of unlinked Indian "islands" surrounded by hostile whites eager to expand their domains.

Though the Justice Ministry has appealed rulings that order Indians to leave parts of the reservation, tribal leaders argue that the resulting delays only strengthen the position of the white invaders.

"The government is telling us to be patient, that it will all be sorted out in the courts, and we eventually will be victorious," said Mr. de Souza, the Macuxi tribal leader. "But while we wait, we see we are losing our space. More and more ranchers, rice growers and miners are occupying our land, gaining strength and growing more violent."

Thus far, the Indians have remained peaceful, despite the disappearance or killing of some of their number, which they blame on gunmen hired by ranchers and rice-growers. But indigenous leaders vow to resist if the police or the military should ever act to enforce injunctions to throw them off their ancestral lands.

"We're not going to attack anyone, but if we are attacked, we will defend ourselves," said Severino Oliveira Brasil, the chief of Javari village, where several hundred Indians have gathered. "We're not afraid. If we die defending what is ours, that is no problem. Our main weapon is the word of God, but we are well-equipped in our Indian way. We have our bows and arrows."