A new featurette and two teasers have been released for Transcendence, Digital Spy said.

Dark Knight cinematographer Wally Pfister's upcoming sci-fi thriller about the rise of artificial intelligence stars Johnny Depp, Morgan Freeman and Rebecca Hall.

The first teaser clip features footage showing a demonstration by the film's activist group R.I.F.T (Revolutionary Independence From Technology), in which a banner reading "Humans are born, not programmed" is unfurled atop a government building.

The second teaser - titled 'This is just the beginning' - features the voice of Kate Mara (House of Cards) as a R.I.F.T campaigner who outlines the dangers of uploading human brains to super-computer storage ('transcendence').

She calls on viewers to "stop the scientists who invent these machines" and highlights Dr Will Caster (Depp) as a key R.I.F.T target.

A behind-the-scenes video - released March 28 - explores Depp's, Freeman's and Pfister's thoughts on the movie's plot.

It also features a glimpse of Hall's character's dilemma as she watches her husband succumb to an ever-growing thirst for power.

Paul Bettany and Cillian Murphy also feature in the Christopher Nolan-produced film, which opens on April 18 in the US and on April 25 in the UK.