Hollywood loves a sequel, but on Thursday it was an unwelcome one when people of colour were shut out of all the Oscar acting races. Again.

All the 20 lead and supporting actor and actress nominees were white as for the second straight year, the Academy of Motion Pictures Arts and Sciences overlooked critically-acclaimed movies featuring black actors and directors.

Hip-hop hit movie "Straight Outta Compton" failed to get a place in the best picture category, and the Twitter hashtag #Oscarssowhite, which sprung up a year ago, was quickly revived.

Will Smith ("Concussion"), Idris Elba ("Beasts of No Nation"), and Michael B. Jordan ("Creed") were among those thought to be in the running for a nomination but left out.

"The snowstorms in 'The Revenant' are almost as blindingly white as the 2016 Oscars," read an ecard posted on Twitter by Someecards, referring to the movie that was filmed in freezing conditions and won a leading 12 nominations.

“Why did the Oscars announce all the white nominees first?” quipped British comedian Ricky Gervais on Twitter, four days after he hosted the Golden Globes ceremony in Beverly Hills.

Gil Robertson, president of the African American Film Critics Association, the largest such body in the world, said the omissions were disappointing.

"For Sylvester Stallone to be the only nominee for 'Creed' is totally a slap in the face to some of the other people involved in that project," Robertson told Reuters.

"Films are making the bulk of their money in foreign markets so it's going to be a business necessity for the industry to populate their films with the people of the world, who are not only black and brown but all other colours," he said.

The exclusions will likely give comedian Chris Rock, for his pointed remarks on politics and race, some powerful material for his turn as Oscar host on Feb. 28 when the winners are announced. In a promotional Oscar video last week, Rock pours white talcum powder over his hands and claps them.

April Reign, managing editor of BroadwayBlack.com, who identifies herself as the creator of the #Oscarssowhite hashtag, tweeted on Thursday: "A five-minute opening by brilliant Chris Rock will not make up for over 80 years of erasure of marginalized communities."

Reginald Hudlin, who will produce the Oscar ceremony, said that after "an extraordinary number of great performances by black actors that were embraced by audiences and embraced by critics, for them all to get ignored is tragic."