The FBI escalated its investigation into Nevada rancher Cliven Bundy’s 2014 standoff with the federal government Thursday with sweeping raids across the country that resulted in 12 arrests, including that of a Donald Trump campaign coalition co-chair in New Hampshire.

Two of Bundy’s sons were also among those arrested, amid signs that federal authorities are ramping up their efforts against the ultra-conservative, anti-government movement that also inspired the armed standoff in Oregon earlier this year.

Cliven Bundy had long refused to pay fees to the government to allow his cattle to graze on federally controlled public lands – a dispute that escalated to an armed standoff in 2014 when officials tried to seize his livestock. Hundreds of anti-government activists, some heavily armed, flocked to Bunkerville to support the Bundys, and the government ultimately backed down.

A federal grand jury last month indicted Cliven, 69, and his two sons Ammon, 40, and Ryan, 43, on a slew of felony offenses – including armed assault of law enforcement officials and conspiracy against the government – for the high-profile land-use dispute at the Bundy ranch in Bunkerville, Nevada.

The latest arrests mean five members of the Bundy family, Cliven included, are in jail awaiting trial. If convicted, they could each face decades in prison.

Ammon and Ryan Bundy have also been indicted over the standoff in Oregon, which lasted 41 days.



Now two more sons of Cliven – Davey, 39, and Mel, 41 – have also been arrested in a coordinated operation that also involved the arrest of Jerry DeLemus, a 61-year-old New Hampshire co-chair for Trump, the Republican presidential frontrunner.

Those three, along with 11 other new defendants, now face prosecution for their participation in the conflict over government land restrictions. The charges include conspiracy to impede and injure federal law enforcement officers, threatening and assaulting officers, obstruction of justice, interfering with interstate commerce by extortion, and use of firearms for a violent crime.



Cliven Bundy. Photograph: John Locher/AP

The stunning turn of events on Thursday brought the total number of defendants in the case to 19 and indicates that federal prosecutors are aggressively targeting the Bundy family and their rightwing supporters who have for years protested against the federal government’s regulations on public lands.



But in February, FBI officials arrested Cliven Bundy while he was on his way to Oregon to support an anti-government militia that had seized the Malheur national wildlife refuge to protest about the federal government’s treatment of local ranchers.



His sons Ammon and Ryan led this year’s takeover of federal lands in Oregon, which began on 2 January and dragged on for more than a month before the final holdouts surrendered to the FBI.

Ammon, Ryan and five other men are now facing felony charges in both the Nevada and Oregon cases and could end up with significant prison time if they are ultimately convicted.

Shiree Bundy, older sister of Davey and Mel, told the Guardian that Davey was arrested on Thursday morning in his hometown of Delta, Utah.

“Anyone who knows my brother [Davey] knows he is the most sweet, calm guy. He is a good person, a father, a husband, a hard worker,” said Shiree, 45, who lives in Orderville, Utah. “He wouldn’t hurt anybody.”

Davey was present in Bunkerville during the 2014 standoff – like many in the family who returned to the ranch to support their father – but he was never violent, according to Shiree. “He stood there with my brothers as they asked them to let our cattle go,” she said. “He didn’t even have a gun on him.”

When the standoff intensified in April 2014, Davey was briefly arrested and cited on misdemeanor charges of “refusing to disperse”.

“They had nothing to hold him on then, and they can’t have anything on him now,” said Shiree, who noted that Davey runs a construction company and has six children, ages one to 14.

This year Davey also told Ammon and Ryan that he was not willing to risk arrest and join them in Oregon, according to Shiree. “When they said, ‘You should be up here,’ Davey said, ‘I’m not going to go to jail again. I have a family and kids to take care of.’”

Booking images of some of the people arrested at the Malheur national wildlife refuge. Photograph: Multnomah County Sheriff/EPA

Mel’s wife, Briana Bundy, said in a brief phone interview that her husband was arrested Thursday and that she didn’t know what charges he is facing.



“I don’t have anything to say except wake the hell up, America. It’s time to decide what side of the line you’re on,” said Briana, 30, who lives in Nevada and has five children, including a newborn baby. “I have my life to figure out. I have five kids now with no provider.”

Mel was present at the Oregon occupation at the beginning of the standoff, but he was not one of the 25 people recently indicted in the Malheur wildlife refuge case.

“All we were doing was protecting our property,” Mel said in an interview with the Guardian last month. “The federal government has overstepped its bounds.”

Cliven, Ammon and Ryan have all been denied bail and remain behind bars.

DeLemus, a Tea Party activist, was present at the 2014 standoff and also traveled to the Oregon occupation this year. The Guardian interviewed DeLemus on multiple occasions at the Oregon refuge in January, and the rightwing activist repeatedly said he was there to try to help negotiate a peaceful resolution.



Last July, Trump announced DeLemus as a co-chair of his “Veterans for Trump” coalition in New Hampshire. His wife, Susan DeLemus, a Republican state representative, did not respond to requests for comment on Thursday.

DeLemus also made headlines last year when he proposed a “Draw Muhammad” art contest as part of an anti-Muslim demonstration.

A Trump spokesperson did not immediately respond to request for comment.

Two of the defendants newly charged this week – Brian Cavalier and Blaine Cooper – are already in federal custody in Oregon for their roles in the Malheur case.

“This investigation began the day after the assault against federal law enforcement officers and continues to this day,” US attorney Daniel Bogden said in a statement. “We will continue to work to identify the assaulters and their role in the assault and the aftermath, in order to ensure that justice is served.”

The new grand jury indictment includes defendants from Nevada, Utah, Idaho, Arizona, Oklahoma and New Hampshire.