BURNS, Ore. -- The small, armed group occupying a remote national wildlife preserve in Oregon has said repeatedly that local people should control federal lands - a sentiment that frustrates critics who say the lands are already managed to help everyone from ranchers to recreationalists.

Overnight Tuesday, a Twitter account purporting to belong to Ammon Bundy, the group's leader, posted a tweet comparing the armed group to civil rights icon Rosa Parks. The tweet was referenced in an earlier version of this story. On Wednesday, Bundy told reporters he doesn't have a Twitter account.

With the takeover entering its fourth day Wednesday, authorities had not removed the group of roughly 20 people from the Malheur National Wildlife Refuge in eastern Oregon's high desert country. But members of the group - some from as far away as Arizona and Michigan - were growing increasingly tense, saying they feared a federal raid.

Arizona rancher LaVoy Finicum said Tuesday evening that he believes federal officials have issued warrants for the arrest of five group members - including himself and Bundy - but Finicum offered no details.

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The FBI in Portland referred calls to the Harney County Joint Information Center, which said in a statement it had no information on arrests or arrest warrants and that authorities were "still working on a peaceful resolution."

Bundy said they would take a defensive position anticipating a possible raid. Late Tuesday, the group moved a large plow vehicle to block the refuge's driveway.

Bundy told reporters Tuesday the group would leave when there was a plan in place to turn over federal lands to locals - a common refrain in a decades-long fight over public lands in the West.

"It is our goal to get the logger back to logging, the rancher back to ranching," said the son of Nevada rancher Cliven Bundy, who was involved in a high-profile 2014 standoff with the government over grazing rights.

The younger Bundy's anti-government group is critical of federal land stewardship. But environmentalists and others say U.S. officials should keep control for the broadest possible benefit to business, recreation and the environment.

Randy Eardley, a Bureau of Land Management spokesman, said the group's call for land ownership transfer didn't make sense.

"It is frustrating when I hear the demand that we return the land to the people, because it is in the people's hand - the people own it," Eardley said. "Everybody in the United States owns that land. ... We manage it the best we can for its owners, the people, and whether it's for recreating, for grazing, for energy and mineral development."

Bob Sallinger, conservation director of the Audubon Society of Portland, said in a statement this week that occupation of the refuge "holds hostage public lands and public resources to serve the very narrow political agenda of the occupiers."

The armed group seized the refuge's headquarters Saturday night. Bundled in camouflage, earmuffs and cowboy hats, they seem to be centered around a complex of buildings on the 300-square-mile high desert preserve.

Finicum said the power was still on at buildings at the refuge. "If they cut it off, that would be such a crying shame. All the pipes would freeze," he said.

Ammon Bundy offered few specifics about the group's plan to get the land turned over to local control, but Finicum said they would examine the underlying land ownership transactions to begin to "unwind it."

The federal government controls about half of all land in the West, which would make the wholesale transfer of ownership extremely difficult and expensive.

For example, it owns 53 percent of Oregon, 85 percent of Nevada and 66 percent of Utah, according to the Congressional Research Service. Taking over federal public lands in Idaho could cost the state $111 million a year, according to a University of Idaho study.

Bundy said the group felt it had the support of the local community. But the county sheriff has told the group to go home, and many locals don't want them around, fearing they may bring trouble. A community meeting was scheduled for Wednesday. Harney County Sheriff David Ward said in a statement the meeting was to "talk about their security concerns and the disruptions that the behavior of the militants on the refuge are causing for our people."

So far, law enforcement hasn't taken action against the group, whose rallying cry is the imprisonment of father-and-son ranchers who set fire to federal land.

The group calling itself Citizens for Constitutional Freedom said it wants an inquiry into whether the government is forcing ranchers off their land after Dwight Hammond and his son, Steven, reported back to prison Monday.

The Hammonds, who have distanced themselves from the group, were convicted of arson three years ago and served no more than a year. A judge later ruled the terms fell short of minimum sentences that require them to serve about four more years.

The takeover comes amid a dispute that dates back decades in the West. In the 1970s, Nevada and other states pushed for local control in what was known as the Sagebrush Rebellion. Supporters wanted more land for cattle grazing, mining and timber harvesting.