An advert by the US National Rifle Association (NRA) has gone viral on social media after it was accused of being an "open call to violence."

The advert which is entitled The Violence of Lies, calls on Americans to join "freedom's safest place" as those who oppose the Trump presidency "smash windows and burn cars."

The minute-long advert shows footage of protestors and marches with narration by conservative media personality and NRA spokeswoman Dana Loesch.

Loesch defended the advert on Fox News saying: "There was nowhere in this video ... where I called for anyone to move toward violence, to silence anyone, or where I called for anyone to even pick up a firearm and enact violence."

Some on social media called the advert "barely a whisper shy of a call for full civil war."

The advert was released in April, but has only now started to pick up online traction and currently has more than a quarter of a million views.

The words by Loesch are similar to those of NRA Executive Vice President Wayne LaPierre, who in February said: "A lot of people, for a lot of reasons, want to blow it all up and tear the whole thing down."

Full advert transcript:

"They use their media to assassinate real news. They use their schools to teach children that their president is another Hitler. They use their movie stars and singers and comedy shows and award shows to repeat their narrative over and over again. And then they use their ex-president to endorse the resistance.

"All to make them march, make them protest, make them scream racism and sexism and xenophobia and homophobia. To smash windows, burn cars, shut down interstates and airports, bully and terrorize the law-abiding — until the only option left is for the police to do their jobs and stop the madness.

"And when that happens, they'll use it as an excuse for their outrage. The only way we stop this, the only way we save our country and our freedom, is to fight this violence of lies with the clenched fist of truth. I'm the National Rifle Association of America, and I'm freedom's safest place."