BURNS, Ore. - The remote high desert of eastern Oregon is the latest flashpoint for anti-government sentiment as armed protesters occupied a national wildlife refuge to object to a prison sentence for local ranchers for burning federal land.

Oregon Sen. Ron Wyden says "outsiders" are to blame for the situation in a rural part of the state. Wyden told The Associated Press he had been briefed by Gregory Bretzing, the FBI special agent in charge in Portland, Oregon. Wyden says the FBI is coordinating with state police and the Harney County sheriff's office, but he declined to offer further details.

Ammon Bundy - the son of Nevada rancher Cliven Bundy, who was involved in a 2014 standoff with the government over grazing rights - is among the people at the Malheur National Wildlife Refuge south of Burns, Oregon. It's unclear how many protesters are at the refuge, but Bundy says they are planning to stay indefinitely.

Ammon Bundy posted a video on Facebook asking for others to join him.

Wyden says he understands why some may be frustrated with federal bureaucracy and poor economic conditions in rural areas. However he says they shouldn't be "misled by some outsiders who seem willing to take the law into their own hands."

Ryan Bundy told The Associated Press Sunday the protesters want to "restore the rights to people so they can use the land and resources" for ranching, logging, mining and recreation.

Ryan Bundy spoke at the Malheur National Wildlife Refuge south of Burns, Oregon. Ryan Bundy says he and others are prepared to occupy the remote federal area indefinitely.

Ryan Bundy says the federal government has been "tromping on people's rights and privileges and properties and livelihoods."

Sheriff David Ward says the men came to Harney County in remote southeastern Oregon claiming to be there in support of local ranchers, but were really there to spark a movement to overthrow the government.

Wyden says he believes most people in the area don't support the protesters.

Militia members came to Burns last month, a small town about 280 miles southeast of Portland, Oregon. They were upset over the looming prison sentences for local ranchers Dwight and Steven Hammond. They went to the wildlife refuge Saturday evening following a rally in Burns to support the ranchers.

The sheriff says he is working with local and federal authorities to keep the citizens in his county safe and to quickly and peacefully resolve the situation that began Saturday evening after a peaceful protest in the nearby town of Burns.

He is asking people to stay away from the Malheur National Wildlife Refuge for their own safety. Ward says he does not think any other parts of the county are in immediate danger.