Media playback is unsupported on your device Media caption The team behind the film Detroit react to clashes in Charlottesville

The Oscar-winning director of a new film about the 1967 Detroit riots says talking about race in the US is "more vital than ever".

Kathryn Bigelow was speaking as Detroit is released in the wake of the violent clashes in Charlottesville, Virginia.

She said she wanted to meet racism "head-on", adding: "To do nothing is not an option".

John Boyega, who stars in the film, said: "We all have a voice and we all have a responsibility to speak out."

'Horrific tragedy'

The London-born actor has shared footage of the clashes on Twitter, in which one person died and 19 others were injured, when a car rammed a crowd of people opposing a far-right rally.

"It's so weird, the timing of everything - but now it makes this movie very necessary, for perspective and also to see just how little has been done, and to hopefully spark a positive conversation."

Image copyright Entertainment One Image caption John Boyega said it was hard to gather his thoughts on the current events in the US

Talking about Charlottesville, Bigelow said: "It's just a horrific tragedy and I feel the urgency to have a conversation about race in America is even more vital than ever."

She added: "Even though this story takes place 50 years ago, it feels, sadly, very much like today and therefore tomorrow. Until there's a meaningful conversation about race in America, I'm worried these events will keep happening."

Image copyright Entertainment One Image caption Kathryn Bigelow was the first woman to win an Oscar for best director

She said she did not see the film, starring John Boyega and Will Poulter, as being "entertainment", but rather "a dramatisation of true events".

To that end, the film mixes in news footage from the riots - and people who were there, including Melvin Dismukes, played by Boyega, and Julie Hysell, portrayed in the film by Skins' Hannah Murray.

Bigelow - the first woman to win a best director Oscar, for The Hurt Locker - added: "If there's the chance for the film to generate a dialogue that's meaningful and positive and can generate some transformation, that would of course be my greatest aspiration.

"Any opportunity to meet head-on with the pervasiveness of racism is really important."

Image copyright Entertainment One Image caption Will Poulter, right, plays a police officer in the film

Boyega said at the Detroit premiere that the racism portrayed in the film felt worryingly contemporary.

He said: "It's crazy - I find it hard to even gather my thoughts on it, it's so unexpected and unfortunate. It's mad, the world is changing."

Boyega, perhaps best known as Finn in Star Wars, plays a security guard tasked with protecting a grocery shop from looters, who then becomes embroiled in the Algiers Motel incident, which left three young men dead.

Asked whether it was a departure from the sci-fi franchise, he said: "The best sci-fi has social commentary. And I have the same commitment for Star Wars as I would for Detroit. I only appear in things I would want to watch."

Will Poulter, who plays a Detroit police officer central to the violence inflicted on residents of the motel, said of the current situation in the US: "I think for a lot of people it's hard to believe it's even happening. It feels like a true regression as far as the human race is concerned."

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