'Rogue One' unveils gritty, grounded new 'Star Wars' story

A Star Wars world with a host of new characters and a new feisty female lead was unveiled at a special fan event on Friday, as the cast of the upcoming film Rogue One discussed the latest chapter of the much-loved franchise.

British actress Felicity Jones said her character Jyn Erso is "incredibly independent" in Rogue One, out in theatres December 16.

"She can be tough when she needs to be but she has, I hope, great humanity as well at the same time, and someone who throughout the film finds a cause and finds those leadership qualities inside of her," the actress told Reuters.

Jones joined Rogue One cast members to kick off this year's Star Wars Celebration in London, which features three days of panels and events for fans.

Mexican actor Diego Luna, who plays Captain Cassian Andor, said Rogue One was the "most grounded film" in the franchise.

He also mentioned that it was centred on a group of rebels fighting for freedom to "change their reality."

Forest Whitaker, who plays Saw Gerrera, said Rogue One director Gareth Edwards shot a "very gritty" film with handheld camera work that made it more "personal and intimate."

Disney released a three-minute reel online on Friday of behind-the-scenes footage that featured action, explosions, green screen sets, new creatures and Stormtroopers wading through calm blue waters on a tropical beach.

Attendees at the event were given an exclusive look at a new trailer not yet released to the public, that featured a glimpse of franchise villain Darth Vader, seen in a fan video from the event uploaded by The Daily Beast.

Producer Kathleen Kennedy had previously said that Darth Vader would return in the film and veteran actor James Earl Jones will reprise voicing the character.

Walt Disney Co resurrected Star Wars with a new generation of characters in December's box office hit The Force Awakens.

The saga will continue in Episode VIII, which wrapped filming this week and will be out in theatres December 2017.