Families of those killed while watching a Batman film in 2012 have written to Warner Bros with concerns about the new Joker film and urging the film studio to join action against gun violence.

Axar.az reports citing BBC.

Twelve people died in a cinema showing The Dark Knight Rises in Colorado.

They included Jessica Ghawi, 24, whose mother Sandy Phillips told BBC News she was "horrified" by the Joker trailers.

The film stars Joaquin Phoenix, who walked out of a recent interview when asked about the film's violence.

Sandy Phillips and her husband, Lonnie, who run Survivors Empowered, an anti-gun violence group, wrote to Warner Bros with three others whose family members were killed, injured or caught up in the 2012 shooting.

Speaking to BBC News, Mrs Phillips said: "When I first saw the trailers of the movie, I was absolutely horrified.

"And then when I dug a little deeper and found out that it had such unnecessary violence in the movie, it just chilled me to my bones because we work with survivors across the country who have been affected by gun violence.

"It just makes me angry that a major motion picture company isn't taking responsibility and doesn't have the concern of the public at all."