Armed protesters have occupied a US government building in Oregon to support father and son ranchers who have been ordered to return to jail.
Dwight Hammond, 73, and his son Steven, 46, were convicted of arson in 2012 but a court ruled their original sentences were too short.
They said they lit the fires to reduce the growth of invasive species and protect their land from wildfires.
The case has riled right-wing activists who resent government interference.
Those occupying the Malheur National Wildlife Refuge centre in Burns said they plan to stay for years and may use violence if police try to evict them.
Local police said "outside militants" had seized the building, and that multiple agencies were working on a solution, the Oregonian reported.
Among those there is Ammon Bundy, whose father Cliven was involved in a stand-off with the government over grazing rights in 2014.
Speaking to CNN, Mr Bundy gave no specific demands but said the action was aimed at helping locals "claim back their lands and resources".
He said that the wildlife refuge had expanded at the expense of ranchers and miners.
But despite the protest Dwight Hammond said he and his son planned to report peacefully to prison on Monday.
His lawyers told Associated Press "neither Ammon Bundy nor anyone within his group/organisation speak for the Hammond Family".
Local pastor Brian Bowman called for the militia to leave.
"Saying we're going to rise up, if we don't get our way we're going to use armed resistance... That's just not right."