LOS ANGELES — Oppenheimer continued its dominance of awards season as it scored several major prizes at the Screen Actors Guild (SAG) Awards on Saturday.

Christopher Nolan's film won best film cast, while Cillian Murphy and Robert Downey Jr won individual acting prizes.

Accepting the top prize on behalf of the cast, Sir Kenneth Branagh said they were all "grateful, humbled and proud".

The evening was peppered with remarks about the actors' strike, which brought Hollywood to a standstill last year.

Paying tribute to the US actors' union, Sir Kenneth said: "Thank you for fighting for us, thank you for every SAG-Aftra member whose support and whose sacrifice allows us to be standing here better than we were before."

He recalled the night last July when the cast of Oppeheimer downed tools at the film's London premiere as the strike began.

"We went from the red carpet, we didn't see the film that night, we happily went in the direction of solidarity with your good selves, so this is a full circle moment for us," he told the audience of actors.

"We are grateful and humbled and proud not just to be in Nolan's masterpiece, but proud to be in your company."

The film, about theoretical physicist J Robert Oppenheimer, described as the father of the atomic bomb, is almost certain to win best picture at the Oscars next month following its success at SAG and other precursor ceremonies.

The prize for best film cast is seen as the top honor at the SAG Awards in the absence of a best picture category. Winners at the annual ceremony, held in Los Angeles, are voted for by other actors.

Irish actor Cillian Murphy said his win was "extremely, extremely special to me, because it comes from you guys".

He recalled: "Twenty-eight years ago when I was trying to become an actor, I was a failed musician, and I felt extremely like an interloper, but looking out on all of you guys here today, I know I'm part of something truly wonderful, so thank you so much."

Best actor had been seen a two-horse race ahead of the Oscars on March 10, but Murphy's win gives him significant momentum over his nearest rival, Paul Giamatti of The Holdovers.

Elsewhere, Killers of the Flower Moon star Lily Gladstone was named best leading actress — giving her own Oscars campaign a significant boost.

"This has been a hard year for all of us, those of us in this room, those not in this room, I'm so proud that we have gotten here in solidarity with all of our other unions," she said in her acceptance speech.

"It's truly a gift that we get to do this for a living. That's the win, getting to be here, getting to be on set, getting to tell stories. We bring empathy into a world that so needs it."

She added: "It's so easy to distance ourselves, to close off, stop feeling, and [actors] all bravely keep feeling, it brings people out of the shadows, it brings visibility."

Gladstone's win leaves the Oscars category for best actress too close to call, following Poor Things star Emma Stone's victory at last week's Baftas.

The Holdovers star Da'Vine Joy Randolph was named best supporting actress, a prize she has won consistently throughout awards season and she is almost certain to take at the Oscars.

"I wake up every day overwhelmed with gratitude to be a working actor," she said. "In what other profession are people able to live so many lives and touch so many hearts of those they have never gotten to meet?"

She added: "For every actor out there still waiting in the wings for their chance, let me tell you your life can change in a day, it is not a question of if, but when — keep going."

Oppenheimer's Robert Downey Jr, who has similarly been dominating his category, was named best supporting actor.

He described the award as "incredibly meaningful", and acknowledged his Oscar front-runner status by asking: "Why me, why now, why do things seem to be going my way?"

Winners in the television categories included Ali Wong and Steven Yeun for Netflix's road rage series Beef, and Pedro Pascal for post-apocalyptic drama The Last of Us.

Ayo Edebiri and Jeremy Allen White were also recognized for kitchen comedy The Bear, while Elizabeth Debicki won best drama actress for playing Princess Diana in The Crown.

The Bear was named best ensemble comedy cast, while Succession won best ensemble drama cast for its critically-acclaimed fourth and final season.

"Not only did we all get to work on one of the best television shows, maybe ever, but we made friends for life," said actor Alan Ruck as he accepted the prize on behalf of the cast.

Tributes were paid to Matthew Perry, Harry Belafonte, Sir Michael Gambon, Tina Turner, Angus Cloud, Glenda Jackson, Alan Arkin, Julian Sands, Lance Reddick, Lee Sun-kyun, Tom Wilkinson, Andre Braugher and Chita Rivera in the show's In Memoriam segment.

The Devil Wears Prada stars Meryl Streep, Emily Blunt and Anne Hathaway were reunited to present the first award of the night.

Streep initially appeared to accidentally walk straight into the microphone stand — before explaining to the audience she did not have her glasses with her, or the envelope containing the winner.

The two actresses who played her on-screen assistants in the 2006 film then appeared with the envelope and glasses, before the trio delivered a joyous sketch featuring several of the movie's most famous lines.

Presenting another category, Melissa McCarthy asked Billie Eilish to sign her forehead as she told the singer what a huge fan she was, and the casts of Modern Family and Breaking Bad reunited to present the awards for best comedy and drama ensemble cast respectively.

The SAG Awards were streamed around the world on Netflix for the first time, something host Idris Elba referred to as he opened the ceremony.

"Personally, I can't wait to get home, and have Netflix recommend this show to me," the Wire star joked.

He also acknowledged what a "difficult time" it had been for actors during the recent strike, adding: "I want to take a moment to honor and appreciate all of you, both here and watching at home, who stood up in solidarity and support."

Elba said the ceremony being streamed instead of broadcast on a TV network meant actors could swear in their acceptance speeches — but he urged them not to go "full Succession level".

"Here's a good rule of thumb, don't say anything you wouldn't say in front of Oprah," he said, to an audience which included Oprah Winfrey herself.

The Morning Show star Jennifer Aniston and Maestro's Bradley Cooper presented this year's lifetime achievement prize to veteran singer and actress Barbra Streisand.

"All of us in this room and far beyond have been inspired by Barbra's magic," Aniston said. "Barbra did not just pave the way for us women, she bulldozed it."

Accepting her award, Streisand joked it was "such a wonderful award to get, because you know in advance you're going to get it".

Recalling her childhood, she said: "I didn't like reality, I wanted to be in movies. Even though I knew I didn't look like the other women on screen. My mother said 'you'd better learn to type'. But I didn't listen. And somehow, some way, it all came true."

"It's a privilege to be part of this profession. For a couple of hours, people can sit in the theater and escape their own troubles — what an idea."

She paid tribute to her fellow actors and directors, concluding: "I've loved inhabiting that magical world of the movies with you." — BBC