BURNS, Ore. — The armed occupation of an Oregon wildlife refuge had dwindled by Thursday after officials arrested nearly a dozen people involved over the previous two days and the group’s leader, who was among the people arrested, again called on the few remaining occupants to go home without using force.

On Thursday evening, the FBI released graphic video footage of the fatal shooting of one of the occupiers earlier this week, seeking to tamp down speculation regarding what happened when LaVoy Finicum, a spokesman for the group, was killed two days earlier.

Authorities had not released any information about the shooting, saying only that one person was killed while others were arrested, and speculation has swirled online about what happened.

Video footage released by authorities, captured by an FBI plane flying overhead, appeared to show Finicum reaching toward his jacket before Oregon State Police troopers shot and killed him.

“On at least two occasions, Finicum reaches his right hand toward a pocket on the left inside portion of his jacket,” Greg Bretzing, special agent in charge of the FBI’s Portland division, said at a news conference. “He did have a loaded 9 mm semi-automatic handgun in that pocket.”

Bretzing said that Finicum said something to authorities before he was shot, but he did not say what that was. The shooting is being investigated by local authorities.

The news conference came as the occupation stretched into Thursday night with four people at the refuge and roadblocks still closing off the facility, officials said.

Authorities this week have also revealed details about what they observed in this area in the weeks leading up to and since the siege began, including reports of threats and intimidation before the takeover and, in one case, concerns about whether the armed group would try to move from the remote Malheur National Wildlife Refuge into a more populated area.

Three more people were arrested Wednesday, making a total of 11 arrests related to the ongoing refuge takeover. Others have also left the facility without being arrested, authorities say.

The group’s leader, Ammon Bundy, had called on those few still remaining at the refuge to give up the occupation.

“Turn yourselves in and do not use physical force,” Bundy, who was arrested Tuesday, said in a statement, his second such appeal since his arrest Tuesday.

He urged supporters to know that “the world is listening,” and said he plans to “use the criminal discovery process to obtain information and government records.” Bundy also disputed the suggestion that he and the others at the refuge were “armed occupiers,” instead saying that his group had been visiting residents in the region, “educating people and getting them to move towards freedom.”

Bundy has previously called for the people at the refuge to leave and asked that they be allowed to leave without being prosecuted. He and four other people involved in the occupation, including his brother, Ryan, were arrested Tuesday afternoon following gunfire that erupted when the protesters were stopped on a highway outside the refuge.

Another person, later identified as Finicum, was killed after refusing to surrender during that encounter. On Thursday, before video footage of the shooting was released, Bundy said there were lingering questions about what had happened.

“We only had guns for our protection and never once pointed them at another individual or had any desire to do so,” Bundy said in his statement Thursday. “The people have a right to bear arms for their own protection. We never wanted bloodshed.”

Bundy had said that he was “anxiously waiting to review this video,” adding, “Questions must be answered.”

On a road outside the refuge Thursday, a small group of reporters remained gathered on the shoulder next to a roadblock, but there was little activity and few vehicles were seen coming or going. In the afternoon, law enforcement vehicles were seen speeding toward the refuge.

The Federal Aviation Administration said Thursday morning that it had established no-fly zones in the area, one over the wildlife refuge and another over a nearby airport. While there had been no visible law enforcement presence for miles around the refuge during the nearly month-long occupation, an FBI affidavit signed Tuesday and filed in federal court outlined how authorities monitored the situation through information readily provided by the group.

Since the wildlife refuge takeover on Jan. 2, “the occupiers have continually posted to various social media accounts and conducted interviews with news media,” the affidavit stated.

In addition to watching this continuous stream, federal agents also spoke with residents and law enforcement officials in the area. At one point, concerns were raised about whether the occupiers would remain at the refuge, which was remote and empty when the group arrived.

The day the occupation of the wildlife refuge began, the affidavit stated, an agent with the Bureau of Land Management said he was told by a county sheriff’s officer that the group in control of the refuge “had explosives, night vision goggles, and weapons and that if they didn’t get the fight they wanted out there they would bring the fight to town.”

The affidavit also states that problems began well before the takeover. A woman wearing a Bureau of Land Management shirt told agents that two people — one of whom was arrested Tuesday — confronted her at a grocery store. The people shouted at her and threatened to burn her house down, she said.

The arrests Tuesday and Wednesday, along with the blockade around the facility, marked a sharp shift in the simmering standoff in southeastern Oregon, coming nearly a month after the armed protesters headed to the refuge and said they were acting to support two local ranchers sentenced to prison over arson charges. The confrontation has drawn new attention to long-standing frustrations with federal management of land in the West, where the government is the main landlord across much of the region.

These arrests were “the first steps to bring this occupation to a conclusion,” Bretzing, the FBI agent, said this week. Speaking at a news conference, Bretzing said anyone who wanted to leave could do so, but they had to go through a checkpoint where they would be identified.

The FBI put the blame for the roadside violence squarely on the occupiers.

“They had ample opportunity to leave the refuge peacefully,” Bretzing said. “And as the FBI and our partners have clearly demonstrated, actions are not without consequences.”

On Wednesday, Bundy and the six others arrested in Oregon made their first court appearance before Magistrate Judge Stacie F. Beckerman. They all pleaded not guilty and were ordered to remain held, with another hearing scheduled for Friday afternoon.

After arresting eight people in Oregon and Arizona on Tuesday, the FBI and Oregon State Police moved to isolate those remaining at the refuge. In recent weeks, the refuge had curious onlookers freely come and go for self-guided tours.

By Wednesday, officials had set up checkpoints on the roads leading in and out of the refuge, saying they would arrest anyone who tried to go in and calling on those still inside to travel through the checkpoints and leave.

Before these checkpoints were set up early Wednesday morning, though, “several vehicles are known to have left the area,” the FBI said in a statement. Eight people ultimately left the refuge on Wednesday; three were arrested by the FBI on Wednesday afternoon and early evening and the others released.

The three people arrested on Wednesday were Duane Leo Ehmer, 45, of Irrigon, Ore.; Dylan Wade Anderson, 34, of Provo, Utah; and Jason S. Patrick, 43, of Bonaire, Ga.

The FBI said that all of them had been in contact with federal agents and turned themselves in at checkpoints outside the refuge without any incident. Like the eight people arrested a day earlier, they face felony counts of conspiracy to impede officers of the United States from discharging official duties through the use of force, intimidation or threats.

The FBI, in a statement Wednesday night, said that it continues to work with other agencies “to empty the refuge of the armed occupiers in the safest way possible.”

Some local residents have cheered what appears to be the beginning of the occupation’s end. Alesa Wyllie, who works as a teaching assistant for special-needs students, said she would normally go to a student’s home not far from the refuge for tutoring. But since the standoff began, she said her supervisors had told her not to go there.

“He needs me to get out there. This kid has not had services since Christmas because of this,” Wylie said Thursday morning. She added: “Some of these people have families and kids of their own. How would they feel if their kid’s needs were not being met?”

On Thursday morning, with the occupation shrinking, she finally went back to the student’s house and was allowed through after about half an hour.

A live video feed from inside the refuge after the roadblocks were set up showed people who alternated between angry and defeated. One man pushed close to the camera and encouraged other Americans to join.

“Get here, get some,” he bellowed, clutching a gun in both hands. “This is history in the making. There are no laws in this United States now. This is a free-for-all Armageddon.”

But at another point, a man could be heard worrying about his finances and his family at home.

Late Wednesday afternoon, black SUVs and utility trucks carrying floodlights passed through the barricade and parked on a road near the refuge entrance. The lights cast a bright glow on the refuge entrance after the sun set over the sprawling preserve, an area previously noted for being a bird-watching destination.

Three cars and a camper van traveled out of the refuge Wednesday afternoon, but they did not stop at the area where reporters had gathered and disappeared down the road.

William Troy Stevenson traveled from Hermiston, Ore., about 250 miles away, to observe the scene with his son. He came with a long list of questions about who remained at the refuge and why they wanted to stay.

“Are they crazies?” he asked.

Stevenson said he crossed the first road closure on foot and encountered drawn guns when he arrived at another barricade down the road, one surrounded by law enforcement officers.

“They have automatic weapons there. And there’s a lot of them,” Stevenson said of what he saw. “They’re serious. They’ll kill you.”

Another man sitting outside, B.J. Soper, co-founder of the Pacific Patriots Network, an umbrella group for militias in the region, sat in his truck, the engine running and the cab filling with blasts of heat as the temperatures sank below freezing outside.

“I would think it’s over at this point,” said Soper, who came to pick up Patrick.

Soper said he had communicated with the protesters through a liaison and said that at one point, about 10 people remained at the refuge. He urged them to leave, too, but he was not sure they would do so.

“I think the others are going to fight,” he said.

Berman reported from Washington. Jerry Markon, Sarah Kaplan, Adam Goldman and Ellen Nakashima in Washington contributed to this report.

Further reading:

[This story has been updated.]