The San Francisco Board of Supervisors has passed an official resolution that declares the National Rifle Association (NRA) a "domestic terrorist organisation".

Key points: The bill was lodged in the aftermath of the Gilroy Garlic Festival shooting that killed three in July

The bill was lodged in the aftermath of the Gilroy Garlic Festival shooting that killed three in July A member of the San Francisco Board of Supervisors says the NRA "exists to spread pro-gun propaganda"

A member of the San Francisco Board of Supervisors says the NRA "exists to spread pro-gun propaganda" The NRA said it represents Americans from all walks of life, and that "San Fran should be ashamed"

In the wake of a number of recent mass shootings across the US, and specifically the shooting that killed three people at the Gilroy Garlic Festival in San Francisco, Supervisor Catherine Stefani introduced the bill in late July.

It was passed on Tuesday, accompanied by an official declaration denouncing the NRA and calling for urgent gun control action.

"The National Rifle Association musters its considerable wealth and organisational strength to promote gun ownership and incite gun owners to acts of violence," the declaration read.

"The National Rifle Association spreads propaganda that misinforms and aims to deceive the public about the dangers of gun violence.

"The leadership of the National Rifle Association promotes extremist positions, in defiance of the views of a majority of its membership and the public, and undermines the general welfare."

Ms Stefani mentioned the rate of gun ownership in the US — a country with more guns than people, she said — and said that this action was "a step in fighting the negative action of the NRA".

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 57 seconds 57 s Shots fired at garlic festival in Gilroy, California. ( ABC News )

"The NRA exists to spread pro-gun propaganda and put weapons in the hands of those who would harm and terrorise us," Ms Stefani said.

"Nobody has done more to fan the flames of gun violence than the NRA.

"Every country on earth has video games, movies and mental health issues, and yet only the US has gun violence at elementary schools, at the movies, at Walmart."

"The difference is guns. No other country has so many assault rifles on their streets."

The NRA responded on Twitter with a video of its chief executive Wayne LaPierre giving a speech at the group's 2019 annual meeting, and with a call for NRA members to "show them who you are!".

"There are real victims of terrorism — ask those who lost someone in 9/11," the tweet read.

"NRA is the fabric of American society. We are teachers, doctors, cops and everyone who fights for America's freedoms.

"San Fran should be ashamed."

San Francisco said it would assess its relationships with businesses that are affiliated with the NRA.