Media playback is unsupported on your device Media caption Aerial video released by the FBI January 28, 2016 shows a man who had just stepped out of the white pickup truck at a police roadblock

Robert "LaVoy" Finicum, the Oregon militiaman killed by police on Tuesday, reached for a handgun before he was shot, according to the FBI.

The agency has released dramatic footage of the shooting, showing Finicum speeding away from police.

Finicum was a key player in an armed anti-government protest at a wildlife reserve in the state.

The footage released by the FBI shows Finicum's vehicle careering into a snowbank in an attempt to avoid a roadblock.

It comes to a stop after narrowly missing a police officer and Finicum steps out. After briefly raising his hands, he appears to reach for his pocket, where the gun was reportedly later found, and is shot dead.

The white pickup truck carrying Finicum (it is not clear if he was driving) was stopped on Oregon's Highway 395 on Tuesday afternoon in a joint operation between the FBI and Oregon State Police.

A jeep was also stopped. The two vehicles contained members of an armed militia which earlier this month occupied the Malheur national wildlife refuge in protest over sentences handed to two local ranchers convicted of arson.

Both vehicles were initially stopped. Ammon Bundy - the leader of the occupation - stepped out of one vehicle along with another protester, Brian Cavalier, and the driver, who has not been named. Mr Bundy and Mr Cavalier were arrested.

Image copyright Reuters Image caption Robert "LaVoy" Finicum became de facto spokesman for the militia in Oregon

Ryan Payne, another member of the occupation, exited the white pickup but Finicum remained inside. About three minutes later, the white pickup sped off, with police in pursuit.

It then crashed into a snow bank in an attempt to clear the roadblock and Finicum was shot. Three other occupants of the vehicle exited after police fired a tear gas-like substance inside. They were Mr Bundy's brother Ryan, Shawna Cox and another woman who has not been named.

Once they had been held by police, officers gave medical attention to Finicum, some 10 minutes after he had been shot. Three more loaded guns were found in the vehicle, the FBI says.

Greg Bretzing, the special agent in charge of the FBI in Oregon, said the agency had decided to release the full, unedited video "in the interest of transparency".

Four people remain at the wildlife reserve, near the city of Burns, Mr Bretzing said. Several people have left since Mr Bundy, speaking through his lawyer on Wednesday, urged the remaining protesters to stand down.

Mr Bretzing said: "I want to acknowledge the stress and disruption that the occupation of the refuge has caused has to the people of Harney County. We know this is difficult. We know that you want this concluded as soon as possible. We are doing everything we can to bring this to a resolution safely and quickly.

James Cook, North America correspondent, recalls dead militiaman

Image copyright Reuters

In the early days of the Oregon occupation, the militiamen were a mixed bunch. There were the taciturn ones, the braggarts and the loose cannons.

And then there was LaVoy Finicum, a man who seemed to stand apart from the rest. On one foul night in the cold with sleet falling and rumours of a raid flying, Mr Finicum took his rifle and sat on the ground at the entrance to the bird reserve headquarters with the weapon on his lap.

Ignoring scoffs from the assembled reporters, he told me he would resist if police came for him. He had no intention of being caged and, if necessary, he was ready to die.

In the end he appears to have died as he predicted he might, violently and at the hands of the authorities he despised. Whatever the truth of his final moments, LaVoy Finicum leaves behind a large family, reportedly of 11 children.

"I have a 17-year-old daughter," he said. "Thank goodness she's a firecracker, I hope she can hold everything together. I'm a small producer. She'll be able to do it."