The heavily armed rightwing groups who descended on rural Harney County in eastern Oregon on Saturday – to protect the peace, they said – made clear they had no intention of leaving, as the occupation of the Malheur national wildlife refuge entered its second week.

Observers, meanwhile, noted that many such groups were extremist entities with histories of promoting bigotry, racism and violence.

On Saturday, leaders of the militia group, which began its occupation a week previously, said the outside groups were unwelcome and unnecessary.

A day later, the new militias in town said they would stay until the occupation ended, raising further concerns about the potential for violence.

The leaders of the outside groups insist that they aim to act as mediators between the occupiers of the federal buildings, law enforcement and local residents – and say they will provide protection and security for all. They say they do not endorse the armed takeover of the refuge, by occupation leader Ammon Bundy, and want to ensure it does not end with a deadly shootout.

“We are hopeful for a resolution quickly – one that is mutually beneficial for all parties involved,” Brandon Curtiss, president of a group called 3% of Idaho, told the Guardian on Sunday morning. “We are trying to carry a role as a neutral party and a buffer zone.”

Occupier Duane Ehmer rides on horseback through the Malheur national wildlife refuge. Photograph: ddp USA/Rex/Shutterstock

The group 3% of Idaho is one of several loosely organized armed bands with a growing presence at the refuge and in Burns, the closest town. Curtiss, who lives in Boise, Idaho, made headlines last year for his role in anti-Islam protests against that state’s resettlement program for Muslim refugees from Syria.

The Southern Poverty Law Center, a nonprofit that tracks hate groups, has labeled Curtiss and his Idaho group anti-government extremists. So-called “three percenter” groups across the country have faced criticisms for armed protests that advocate positions against immigrants, refugees and minorities.

The “three percenter” moniker alludes to the small percentage of colonials such groups claim fought in the American revolutionary war. About 376,000 people fought for the American army and militias, or about 15% of the 13 colonies’ 2.5 million people, although the standing size of forces was small at any given time.

Anti-government militia groups have grown by one-third in the last year, according to the SPLC.

Curtiss is also a co-founder of the Pacific Patriots Network, another group now stationed in Burns that has a history of controversial armed protests.

Given the heavy presence of firearms in Burns and at the wildlife refuge, many onlookers and reporters have labeled the groups as “militias”. Leaders of the groups said that although they do some military-style training and carry guns, they do not use the militia label.

BJ Soper, from a group calling itself the Central Oregon Constitutional Guard, told residents in Burns at a community meeting on Friday night he was only trying to help keep the peace.

“When you classify us as militia,” he said, “well, I’m no different than you. I’m an American.”

He added: “You don’t have to be afraid of us … we’re your neighbors.”

At the refuge on Saturday, a spokesmen for the Bundy militia publicly criticized the Pacific Patriots Network for bringing more “long guns” – rifles – to the occupation. But leaders of the outside groups said they were armed for their own protection and did not want to antagonize anyone.

“We have security teams,” Curtiss told the Guardian. “Those are the guys that make sure we’re safe.”

Since arriving in Burns, he said, “We’ve had threats on our lives as well as our families.” He added: “We’re more of a community awareness organization that stands up for people’s rights.”

Joseph Oshaughnessy, with a group called the North American Coalition of Constitutional Militias, noted that he himself was not armed, but said he had brought armed men with him to keep everyone protected.

“It’s just for security,” he said.

The new armed groups on Saturday drove around the region, attempting to talk to law enforcement leaders. In the afternoon, some talked briefly with FBI officials stationed at Burns municipal airport. Later, they met with Harney County’s sheriff, Dave Ward, in heavy snow by the local courthouse.

Ward has pleaded for the Bundy militia to end its occupation and has offered to peacefully escort its members out of the state. At his latest press conference, on Friday morning, Bundy said he was not ready to accept the invitation.

Although Bundy and other prominent militia members at the refuge have made clear they do not want the Pacific Patriots Network and other unaffiliated armed militia around, some of the occupiers said they welcomed the men and their firearms.

“I feel great about it. I feel safe,” said Blaine Cooper, an occupier from Arizona who was guarding the front entrance of the refuge on Sunday morning.

“Their role is to keep the peace between the two sides. Obviously, I don’t want to get slaughtered by the feds.”