Robert Downey Jr is among the early winners at the 2024 Oscars, which are taking place in Los Angeles.

The star won best supporting actor for his portrayal of US government official Lewis Strauss in Oppenheimer.

Accepting his award, Downey Jr joked: "I'd like to thank my terrible childhood, and the Academy, in that order.

"I needed this job more than it needed me," he continued. "I stand here before you a better man because of it."

The star also paid tribute to his wife Susan Downey, who he said had found him as a "a snarling rescue pet", adding that she "loved me back to life, that's why I'm here".

The actor, best known for his run as Marvel's Iron Man, has enjoyed a hugely successful Hollywood comeback after serious drug addiction issues which saw him serve a prison sentence more than two decades ago.

He concluded his speech by telling the audience: "What we do is meaningful and what we decide to make is important."

Oppenheimer, directed by Christopher Nolan, also won best editing and cinematography and is the firm favourite to win best picture. However, it has lost several other technical categories.

Instead, the unusual steampunk drama Poor Things won best production design, costume design and make-up and hairstyling.

The Emma Stone film follows an infant whose brain has been implanted into the body of an adult woman, who then goes on an adventure of discovery across the world.

Da'Vine Joy Randolph earlier won the best supporting actress for her portrayal of a school chef who is trying to cope with the death of her son in The Holdovers.

In her acceptance speech, Randolph told the audience: "For so long I have always wanted to be different. And I now I realise I just needed to be myself, and I thank you for seeing me.

"I didn't think I was supposed to be doing this as a career, I started off as a singer, and my mother said to me, go across that street to that theatre department, there's something for you there.

"And I thank my mother for doing that, I thank all those people who have been there for me, ushered and guided me, I am so grateful to you beautiful people out there."

The Zone of Interest won best sound and became the first British film ever to win best international feature. The critically acclaimed Holocaust drama follows a German family who live next to an Auschwitz camp.

In his acceptance speech, director Jonathan Glazer criticised Israel and the ongoing war in Gaza.

"Our film shows where dehumanisation leads at its worst, it shapes all of our past and present," he said. "Whether it's the victims of 7 October in Israel or of the ongoing attack on Gaza, all are victims of this dehumanisation."

Earlier in the evening, the start of the Oscars ceremony was delayed by five minutes as pro-Palestinian protesters gathered outside the Dolby Theatre in Los Angeles.

Elsewhere, Anatomy of a Fall won best original screenplay. The film's director and co-writer Justine Triet joked the Oscar would "help me through my mid-life crisis".

The film follows a woman accused of killing her husband, with the only nearby witness her visually impaired son.

American Fiction was named best adapted screenplay. Its writer Cord Jefferson said: "I've been talking a lot about how many people passed on this movie when discussing it, and I'm worried that sounds vindictive, but it's more a plea to recognise there are many people out there who want the opportunity I was given."

The writer said he understood Hollywood "is a risk-averse industry", but said studios should commission more smaller-scale movies. "Instead of making one $200m movie, try making 20 $10m movies," he said.

Japanese fantasy film The Boy and the Heron also notched an early win, taking best animated feature film and holding off competition from Spider-Man: Across the Spider-Verse.

Other films vying for prizes at the ceremony include Barbie, Maestro and Killers of the Flower Moon.

For the fourth time, the ceremony is being hosted by Jimmy Kimmel. The US chat show host opened with a monologue which reflected on the past 12 months in the film industry.

Recalling the strikes that brought Hollywood to a standstill, Kimmel paid tribute to the efforts made to get a fair deal for actors and writers.

He joked that actors could now stop worrying about "being replaced by AI, and could go back to worrying about being replaced by younger, more attractive people".

Turning his attention to Barbie stars Margot Robbie and Ryan Gosling, he said: "If neither of you wins an Oscar tonight, I would like to say you won something much better, the genetic lottery."

Kimmel also suggested the nominated movies "were too long this year", adding: "When I went to see Killers of the Flower Moon, I had my mail forwarded to the theatre.

"Killers of the Flower Moon is so long," he continued, "in the time it took you to watch it, you could drive to Oklahoma and solve the murders yourself."

Picking out more nominees sitting in the audience, the comic poked fun at Robert De Niro and Jodie Foster, who he observed "were both nominated for Taxi Driver in 1976 and they are both nominated again tonight".

"In 1976 Jodie Foster is young enough to be Robert De Niro's daughter, now she is 20 years too old to be Robert De Niro's girlfriend."

Read more about the films in this year's awards race:

• Poor Things: Emma Stone: Sex scenes in Poor Things are 'honest'
• The Holdovers: The Holdovers: Could it be a new Christmas classic?
• Barbie: Billie Eilish dedicates award to people struggling
• Oppenheimer: Barbenheimer was wonderful for cinema, Murphy says
• American Fiction: White audiences 'too comfortable with black clichés'
• Rustin: The gay civil rights activist history forgot
• The Color Purple: Stars want to make Oprah proud
• Nyad: Netflix film follows woman who braved sharks and jellyfish
• Past Lives: The film on lost love that crosses continents
• Killers of the Flower Moon: Lily Gladstone could make Oscars history
• Saltburn: Director discusses 'revolting' bathtub scene
• May December: Film explores 'disquieting moral ambiguity'
• The Zone of Interest: Auschwitz film was 'like Big Brother' in house next to camp
• Society of the Snow: Society of the Snow film explores cannibalism and survival
• All of us Strangers: Andrew Scott film an 'unforgettable' look at trauma
• Maestro: Why the Bradley Cooper nose row is complicated