GRAVELLY POINT PARK, Virginia – Some two dozen gun-toting activists rallied Monday in a national park near Washington 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 Vanderboegh 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, Vanderboegh 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.

"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," said Vanderboegh.

"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 or 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.

"We are the tip of the Tea Party's spear. We are the IRA to the Tea Party's Sinn Fein," Vanderboegh said, referring to the Irish Republican Army, the main paramilitary force in three decades of violence between Catholics and Protestants in Northern Ireland, and its political wing.

The rally also coincided with the anniversaries of two events that 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.

Laura Sonnenmark, one of a handful of counter-protesters at the rally, held up a sign reading: "Timothy McVeigh was not a hero."

"They think we don't know any better and need them to take over for us," Sonnenmark told AFP.

"Anyone who uses this kind of vitriol to promote themselves should think about who might end up in charge of our country one day," she said, referring to Republican lawmakers who egged on protesters outside the Capitol during the rancorous debate on health care reform.

Amid American flags eerily reminiscent of Adolf Hitler's Third Reich -- with a Roman numeral III in the middle of a circle of stars -- and yellow "Don't tread on me" banners that have become the hallmark of the Tea Party movement, some of the protesters and speakers at the rally said the Holocaust and slavery would not have happened if Europe's Jews and black slaves had been armed.

Mike, an Ethiopian-American taxi driver, watched the gathering with a look of disbelief on his face.

"This is wrong. How are we supposed to know who the sheriff is if everyone is carrying a gun?" he told AFP.

Across the Potomac in Washington, where it is illegal to carry a weapon, another group marched in support of gun rights.

The rallies were held as a poll showed that nearly one in three Americans views the US government as a "major threat" to their freedoms.

Nineteen 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.

The protesters were able to rally with their loaded weapons in a national park because Obama recently signed a bill allowing it.

But that did little to temper their anger 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."