Tuesday marked the fourth day that a group known as Citizens for Constitutional Freedom continued an armed occupation of a federal building in Oregon.

The group seized the headquarters of the Malheur National Wildlife Refuge, a federally owned wildlife outpost in remote Oregon, while the building was empty on Saturday. The armed protesters are calling for the release of local ranchers Dwight Hammond, 73, and his son Steven, 46, who were convicted of setting fires that spread to government land. The occupiers have also vowed to remain in the building until federally owned land is returned "back to the people."

At the head of the occupation are Ammon and Ryan Bundy, the sons of Nevada rancher Cliven Bundy, who led an armed standoff with the federal government in 2014 and notoriously suggested that African Americans were better off as slaves.

The protesters have remained at the reserve in spite of the fact that the Hammonds turned themselves in at the federal prison in California on Monday afternoon and appeared to disavow the occupation.

"Neither Ammon Bundy nor anyone within his group/organization speak for the Hammond family," said lawyers representing the Hammonds.

The FBI has not made an attempt to take back the isolated building and said Sunday it aims to bring a "peaceful" end to the standoff.

"The FBI is working with the Harney County Sheriff's Office, Oregon State Police and other local and state law enforcement agencies to bring a peaceful resolution to the situation at the Malheur National Wildlife Refuge," the agency's Portland office said in a statement, reports CNN.

Meanwhile, Harney County Sheriff Dave Ward publicly called for the occupiers to leave the area.

"The Hammonds have turned themselves in," he said. "It is time for you to leave our community. Go home, be with your own families and end this peacefully."

The protesters, however, said they have no intentions to leave anytime soon.

"We came very well prepared. We're in it for the long haul," said protester John Reitzheimer.

Ammon Bundy also told NBC's TODAY on Monday that the occupiers will resort to violence if the government intervenes in their occupation.

"The only violence that, if it comes our way, will be because government is wanting their building back,'' he said. "We're putting nobody in harm's way. We are not threatening anybody. We're 30 miles out of the closest town."