Updated at 6:24 p.m.

BURNS - Tensions mounted Saturday at the Malheur National Wildlife Refuge, where men involved in an armed standoff clashed with conservationists and accused government workers of harassing their families.

As the standoff led by Arizona businessman Ammon Bundy entered its third week at the refuge headquarters, accusations swirled that Child Protective Services workers had begun visiting some of the occupiers' families.

Meanwhile, a visit to the refuge from land conservationists devolved into a shouting match, complete with a bullhorn and name-calling, after the group tried to address news reporters.

The spectacle erupted just after occupiers arrived for a morning news briefing with a wicker basket full of surveillance cameras they removed Friday from a transformer station outside Burns. LaVoy Finicum, a spokeman for the occupiers, claimed the cameras had been installed by the FBI.

"This in my opinion is unreasonable search," said Finicum, referencing the Fourth Amendment as he invited the agency to "come pick them up."

Ammon Bundy and his armed anti-government followers took over the refuge Jan. 2, two days before father and son ranchers from Harney County were to report to federal prison for setting fires on federal land. The occupiers want Dwight and Steve Hammond released and to see the federally owned land returned to local ranchers and loggers.

Environmentalists faceoff with refuge militants 11 Gallery: Environmentalists faceoff with refuge militants

In the days since, they've been joined by a growing stream of supporters as well as counter protesters who say the land should remain public.

Members of the Center for Biological Diversity, led by executive director Kieran Suckling, arrived at the Saturday morning news briefing carrying signs and waiting for an opening to speak against the seizure of the wildlife refuge 30 miles south of Burns.

When Finicum finished addressing reporters, Suckling picked up the mic.

"The center has been tangling with the Bundys since the mid-1990s," Suckling said of the Arizona-based nonprofit, which claims more than 990,000 members and activists dedicated to protecting wild places and endangered species. But before Suckling could finish, the occupiers started yelling and booing.

"We're here to speak up for public land, which belongs to the public," he continued over the clamor. "These people are trying to take the land away."

The occupiers, who have repeatedly defended their armed standoff by arguing it is a form of free speech, booed and shouted down the conservationists who visited Saturday with the same stated purpose.

Pete Santilli, one of the occupiers, pulled out a bullhorn and started shouting "communist" and "fascist." He then flipped on a siren and said, "You're under arrest for bull****ting."

Suckling and his group stopped talking and instead pointed to the signs they were carrying. "STOP BUNDY LAND GRAB," one read.

Amid the drama, occupiers said they're concerned the federal government is targeting their families to punish them for their standoff at the refuge. Finicum, who runs a foster care program at his Arizona ranch, said state officials had removed four young boys from his care.

The governor's office "came down and ripped my boys out of my home," he said.

News that Child Protective Services workers had visited the home of at least one standoff participant spurred a "call to arms" for Bundy's supporters in Arizona to intervene should government workers attempt to take children from the home, said Jon Ritzheimer, a prominent member of the Bundy group.

The occupiers have grown increasingly bold in their denunciations of the government, from accusing it of using family members as "hostages" to posing as members of Bundy's group in an attempt to confuse the public.

Their long-term plans for the standoff remain unclear, though Bundy has repeatedly said the group won't leave until the refuge is divvied up among area landowners or they feel confident that local residents can accomplish that goal on their own.

Neither Bundy nor his brother, Ryan Bundy, made an appearance at Saturday's briefing.

Finicum said the occupiers hope to hold a community meeting Monday to outline their exit strategy. The group had to cancel plans for one Friday after they were denied access to a community space at the Harney County Fairgrounds. Ammon Bundy is expected to outline the group's goals in a PowerPoint presentation at the meeting.

As the occupation draws increased backlash from environmentalists and public lands activists, its ranks are growing as supporters trickle in from across the country.

KrisAnne Hall, an attorney and prominent face in the patriot movement, will visit Burns on Monday to host two nights of workshops at the county fairgrounds. An assistant for Hall said she will lecture community members on two topics: sovereignty of the state and the constitutional limits of the federal government's control.

In the meantime, the Bundy group won't hold a news conference on Sunday.

--Kelly House

khouse@oregonian.com

503-221-8178

@Kelly_M_House