The site commander, police Lt. Alex Melo, explained officers were "waiting for the order, and understand it can come at any time."
But the order still had not arrived after a tense, daylong standoff. Frightened residents wondered why law enforcement came without an order to enter, and federal public defenders who have worked on the protracted legal battle over the space tried to mediate.
"This is absolutely arbitrary. They can't enter without an order," said public defender Daniel Macedo. "If they did, they could be charged with a crime, with abuse of authority. It could be a blood bath, which could look really bad for the government of Brazil and the state."
The indigenous group includes men and women of about 10 ethnicities—mostly Guarani, Pataxo, Kaingangue and Guajajara—who have been squatting for years in 10 homes they built on the site of an old Indian Museum, abandoned since 1977.
The police arrived early in the morning and surrounded the compound. By noon, the residents locked the main gate. As supporters arrived, the Indians lowered a wooden ladder over the brick wall surrounding the complex to let them in, later pulling the ladder back up.
During the nerve-racking wait on Saturday, the squatters painted their faces and bodies and donned elaborate headdresses, at times playing rattles and flutes or whistling bird calls. Some displayed ornamental bows and arrows over the wall and through the gate separating them from the black-clad police in body armor.
The settlement and the remains of the building that lodged the museum are adjacent to the Maracana, which is being refurbished to host the opening and closing ceremonies of the 2016 Olympics and the final match of the 2014 World Cup.
Blighted streets around the stadium are also to undergo a vast transformation to become a shopping and sports entertainment hub, complete with parking lots. Most of a favela, or shantytown, about 500 meters away has already been demolished to make way for the new development.
The governor of Rio de Janeiro, Sergio Cabral, told a news conference in October that the building's razing is necessary for hosting the World Cup.
"The Indian Museum near the Maracana will be demolished," Cabral said then. "It's being demanded by FIFA and the World Cup Organizing Committee. Long live democracy, but the building has no historical value. We're going to tear it down."
However, a letter from FIFA's office in Brazil to the federal public defender's office published in the newspaper Jornal do Brazil said that the soccer authority "never requested the demolition of the old Indian Museum in Rio de Janeiro."
The indigenous have been resisting their possible eviction for months, operating with little or no information from authorities about what to expect, or what alternatives are available to them, said their leader Carlos Tukano.
"I know they are going to come in, and our proposal is to remain firm, but without moral or physical aggression," he said. "We cannot fight them with bows and arrows; they are armed."
Most of the approximately 30 Indians who live there and about 200 sympathizers packaged the compound Saturday to discuss how to peacefully deal with a possible police action. Several men, masking their faces with shirts, climbed high into the upper floors of the tumble-down building and surveyed the scene with professional bows and arrows.
The squatters believe they have history and the law on their side.
The crumbling mansion with soaring ceilings that housed the old museum was donated by a wealthy Brazilian to the government in 1847 to serve as a center for the study of indigenous traditions.
After the museum closed more than three decades ago, Indians of various ethnicities started using it as a safe place to stay when they came to Rio to pursue an education, sell trinkets in the streets or get medical treatment.
"They would come here without money, without knowing anyone, and sleep in the streets," Tukano explained. He himself is from a village deep in the Amazon. "We made this our space."
The head of Rio state legislature's Human Rights Commission, representative Marcelo Freixo, called for the need to stay calm and avoid violence.
"Conflict here is not in anyone's interest," he said before addressing the squatters and supporters inside the compound. "If there is a judicial order, the police will have to enforce it, but we have avoid any injuries with dialogue."
As he spoke, state public defender Eduardo Newton proposed an alternative legal tactic.
Under state law, Newton said, there can't be a mass eviction without proper legal proceedings. With group approval, he began gathering documents that would prove that more than 10 families lived on the grounds so he could try for a rushed stay on the eviction notice.
Police, meanwhile, police continued to stand guard the compound.