The film industry's magazine of reference called US movie studios, producers and the media to account Tuesday over the lack of diversity in Hollywood, with a cover story entitled "Shame on us."

Variety magazine added its weighty voice to a rising chorus calling for more inclusivity towards minorities in Hollywood, after a second straight year of all-white Oscar acting nominations triggered major controversy.

"In 2015, America's age-old struggle over civil rights centered on police violence. Gunshots too often killed unarmed black citizens," the magazine wrote.

"This year, the nation's battle over identity and inclusion has found a new focus: Hollywood."

Spurred to act by the uproar, the Academy of Motion Picture Arts and Sciences, which awards the Oscars, on Friday promised "historic action" to redress the balance and double its number of women and minority members by 2020.

But Variety said the problem had roots far deeper than the 89-year-old academy itself.

"The Hollywood studio hierarchy remains an exclusive club chaired by white men and one white woman. The big talent agencies have almost no minority partners. And the media that cover it all -- Variety included -- employ only a few people of color," it said.

Variety spoke to three of the six major Hollywood studios who agreed to go on the record about the problem.

"We need to have a diverse workforce reflecting the diversity in society and we're working toward that," it quoted the chairman of Walt Disney Studios, Alan Horn, as saying.

Studio bosses including Brad Grey, chairman of Paramount Pictures, acknowledged the need for studios to double down on their diversity efforts.

Kevin Tsujihara, chairman and CEO at Warner Bros, called last week's announcement "a great step toward broadening the diversity and inclusivity of the Academy and, by extension, the industry."

"Entertainment is a global business and the content we produce and its creators need to reflect the diversity and different perspectives of the worldwide audience we serve," he said in a statement.

"At Warner Bros we’re committed to this goal, but there is more we must and will do."

Three leading civil rights groups said they had sought a meeting with the trustees of the Academy and other film industry leaders to address the challenge.

The lack of diversity was a complex issue, the National Urban League, the National Action Network and the National Coalition on Black Civic Participation said in a joint statement.

"Award nominations translate into box-office success and the potential for box-office success determines which projects are greenlighted," they said.