Hollywood actors and entertainers have joined forces in a video promoting Demand a Plan, a grassroots effort to curtail gun violence in the aftermath of the Sandy Hook Elementary School massacre.
The Hollywood Reporter website said Friday that the effort is spearheaded by the Mayors Against Illegal Guns campaign, launched in July after the Aurora, Colo., movie theater shooting.
Since then, a petition demanding gun reforms has gathered more than 700,000 signatures.
Among the stars in the 90-second public service announcement are Beyoncé, Jamie Foxx, Gwyneth Paltrow, Michelle Williams, Jon Hamm and Conan O'Brien.
"How many more?" they ask in the bleak, black-and-white video. "How many more colleges? How many more classrooms? How many more movie theaters? How many more houses of faith?"
Jennifer Aniston, Reese Witherspoon, Paul Rudd, Will Ferrell, Sarah Silverman,
Ellen DeGeneres, Julianne Moore and Chris Rock also are among the dozens of stars asking viewers to "demand a plan" for gun law reforms.
According to demandaplan.org, the movement seeks to pass gun laws that require background checks for every gun sold in the US, ban assault weapons and high-capacity magazines and make gun-trafficking a federal crime.
The video was released shortly after the National Rifle Association, the powerful US gun lobby group, on Friday called for armed guards at every US school and rejected the notion that curbs on weapons would protect children in the wake of last week's Connecticut school massacre.
In a rare press briefing, NRA Chief Executive Wayne LaPierre gave an impassioned speech that blamed the media for glorifying violence and perpetuating the idea that tighter gun restrictions would reduce mass shootings.
"They perpetuate the dangerous notion that one more gun ban — or one more law imposed on peaceful, lawful people — will protect us where 20,000 others have failed," LaPierre said at the event at a hotel near the White House.
"The only thing that stops a bad guy with a gun is a good guy with a gun."
His approach was rejected by gun control activists who have revived demands for a ban on assault rifles and big ammunition clips after the Newtown, Connecticut killings, which followed a series of mass shootings at schools and public places.
New York Mayor Michael Bloomberg
said the NRA offered "a paranoid, dystopian vision" of a more violent country. "While they promote armed guards, they continue to oppose the most basic and common sense steps we can take to save lives - not only in schools, but in our movie theaters, malls, and streets," he said in a statement.
LaPierre, twice interrupted by hecklers who were hustled out, suggested a range of ways to prevent violence besides the school guard program, including better treatment of mental illness and cracking down on gory video games and films.
The NRA had largely been silent since last Friday, when 20-year-old Adam Lanza used a high-powered rifle to shoot dead 20 young children and six adults at close range at the Sandy Hook elementary school.
The massacre of so many children provoked national outrage that some see as marking a tipping point for sweeping federal legislation to restrict weapons and ammunition and a law requiring background checks on buyers before all gun purchases.
US President Barack Obama
has formed an interagency group led by his cabinet members to come up with specific proposals by January that could include legislation and executive action.