Hundreds of gun activists descended on Washington, D.C., and neighbouring Virginia on Monday to trumpet their constitutional right to bear arms and rail against what they perceive to be a socialist takeover of their country.

A nurse from Knoxville, Tenn., and her husband listen to remarks as armed protesters rallied for their rights at a "Restore the Constitution" demonstration at Fort Hunt Park in Alexandria, Va., on Monday. (Toby Jorrin/Associated Press) Many of those who gathered at Washington's National Mall carried replica firearms, but across the Potomac River in Virginia — where it is legal to openly carry some weapons — 75 to 100 people at a national park were packing real rifles, pistols and rounds of ammunition under the watchful eye of state and park police.

"We're in a war," Larry Pratt, executive director of Gun Owners of America, told a largely male crowd at the foot of the Washington Monument.

"They are coming for our freedom, for our money, for our kids, for our property. They are coming for everything because they are a bunch of socialists," he said.

Pratt urged the crowd to organize as the November mid-term elections loom, and work to ensure that only pro-gun politicians get elected while those who advocate gun control are shut out. His pleas came despite the fact that there are no proposals coming from the White House or Congress for new gun control laws.

In fact, a year ago President Barack Obama rubber-stamped a law that allows Americans to carry guns in national parks. At the time, the National Rifle Association praised the new law and the organization wasn't actively involved in Monday's rallies.

Another protester shouted to the crowd: "Our right to have a gun doesn't come from Barack Obama, it comes from God. We have a right to protect our families."

One woman said, "It lets a criminal know immediately that I am not weak, not unprotected, and that I am prepared to defend myself."

Armed protests appear to be a growing trend in the U.S. In dozens of states, groups from the "open carry" movement are converging on coffee shops and restaurants with holstered handguns in clear view.

There has also been a rise in the number of armed militia groups and anti-government patriot groups.

Last month in Michigan, nine members of a Christian militia group were charged with plotting to kill a police officer and then gun down other officers attending his funeral.

Monday's protests came on the 15th anniversary of the bombing of the Oklahoma City federal building and the 17th anniversary of the attack by U.S. federal agents on armed and fortified Branch Davidian cult members in Waco, Texas.

Organizers of the rallies said that was simply a coincidence. They insisted the date was selected to commemorate the battles of Lexington and Concord in 1775, which were the first military engagements of the American Revolutionary War.

With files from The Associated Press