The FBI on Thursday released a video investigators say shows one occupier of an Oregon wildlife refuge reach for his jacket pocket before being shot dead by law enforcement, after speeding away from a traffic stop where the group's leader was arrested.

Authorities said 54-year-old Robert LaVoy Finicum, a rancher from Arizona who acted as a spokesman for the occupiers at the Malheur National Wildlife Refuge, was armed when he was stopped by police and killed on Tuesday afternoon.

The aerial video taken by a law enforcement aircraft showed Finicum speed away from authorities in a white truck and nearly strike an FBI agent, while trying to evade a police barricade before barreling into a snowbank and exiting the car.

The grainy aerial footage shows Finicum raise his hands in the air and then turn and flail his arms, moments before he is shot by Oregon State Police troopers, according to the FBI.

Greg Bretzing, special agent in charge of the FBI's Portland office who narrated the video for reporters, said Finicum can be seen reaching for his jacket pocket. But a lack of focus in the video makes it difficult to discern Finicum's precise movements prior to the shooting.

Bretzing told reporters at an evening news conference in the rural community of Burns, Oregon that while the video showing Finicum's death was potentially upsetting, it was released "in the interest of transparency."

The occupation began when leader Ammon Bundy and at least a dozen followers took over a small cluster of buildings at the refuge on Jan. 2, in a flare-up in the so-called Sagebrush Rebellion, a decades-old conflict over federal control of millions of acres in the West.

Police and federal agents kept their distance from the site, 30 miles (48 km) from the small town of Burns in Oregon's rural southeast, in an effort to avoid a violent confrontation.

But on Tuesday, Bundy and his leadership team left the refuge to speak at a community meeting in John Day, Oregon, and were stopped by law enforcement. The stop led to Finicum's fatal shooting and the arrest of Bundy, along with four others.

Bretzing said four occupiers remained holed up at the refuge compound on Thursday night, as authorities sought to negotiate with them to leave. According to the FBI, three of the nine people to have left the refuge have been taken into custody.

Following his initial court appearance in Portland on Wednesday, Ammon Bundy urged the holdouts to stand down, saying he would continue the fight in court.

Reactions to the takeover by Burns residents have ranged from sympathy for two imprisoned local ranchers whose plight began the protest, to dismay at the armed occupation by individuals seen as outsiders.