GRAVELLY POINT PARK, Virginia -- Several dozen gun-toting activists rallied Monday in a small national park near Washington DC to issue dire warnings that the United States could face civil war unless big government stops eating away at their rights.

"This isn't about gun laws -- this is about liberty, about restoring the constitution," anti-government activist Michael van der Boegh told AFP at the sparsely attended rally of mostly white, middle-aged men.

One of several speakers who addressed the crowd from the back of a white pick up truck, Van der Boegh has used Internet postings in the past to call on Americans unhappy with a new law reforming the health care system to throw bricks through the windows of politicians' offices who voted for it.

On Monday, he warned that the United States could face a new civil war if the administration tries to force through health care reforms or any other laws the activists feel would erode their constitutional rights.

"My call to break windows and all the work I do is to call attention to the fact that civil war could happen in the United States," he said.

"If government doesn't rein itself in, we will find ourselves in civil war. What I am doing is jumping out in front of the bus carrying all of our kids and warning that we could face civil war."

"With the passage of the health care bill, they said 'you will' and we say 'Hell no,'" he said, pointing his walking stick Towards the US Capitol across the Potomac River.

By their own admission, the activists at the rally, some of whom had rifles slung over their shoulders and loaded pistols in hip holsters, represent a tiny minority of the US population.

But the rally was held against the backdrop of a vocal anti-government "Tea Party" movement that has gained nationwide attention, and polls showing deepening public dissatisfaction with government.

It also was held on the anniversaries of two events that have have become touchstones for white extremists -- the fiery end of a 51-day FBI siege of a Branch Davidian cult compound in Waco, Texas in 1993, and the bombing on the same day two years later of a federal building in Oklahoma City in a revenge attack by Timothy McVeigh.

The Oklahoma bombing, the most destructive act of domestic terrorism in US history, killed 168 people.

Meanwhile, a poll made public Monday by the Pew Research Center found that nearly one of three Americans view the US government as a "major threat" to their freedoms.

Just 19 percent say they are "basically content" with the federal government, against 56 percent who say they are "frustrated" and 21 percent who describe themselves as "angry," the Pew Research Center survey found.

Only 22 percent say they trust Washington to do what is right almost always or most of the time, according to the survey, which had an error margin of plus or minus four percentage points.

The first time Pew asked the question, in 1958, 73 percent of Americans said they trusted the government. In mid-1994, just 17 percent said the same.

The protesters were able to rally, with their weapons, in a national park because Obama recently signed a bill allowing it. But that did not temper the anger displayed against the first African American president.

"He's not my president. He's trampling on our constitutional rights, " said Tim Hammond from California.

"Take the first amendment and the hate crimes bill passed last year. You can't quote parts of the Bible now because it might offend homosexuals and I disagree with that," he said.