Billie Joe Armstrong wrote 'Bang Bang' from the ''viewpoint of a mass shooter''.

The 44-year-old musician has revealed the lyrics for the track on Green Day's 12th studio album titled 'Revolution Radio', were based on the Isla Vista killings, which took place in Santa Barbara in 2014 and saw the ''deranged'' student Elliot Rodger kill six people and injure another 14.

Speaking in this week's issue of NME magazine, the dark haired punk rocker said: ''A couple of years ago, in the spring of 2014, I wrote the song 'Bang Bang'. I wrote it coming from the viewpoint of a mass shooter [after what] happened in Santa Barbara. This young man was clearly deranged and had a Facebook manifesto about how 'no girls will f**k me so I'm going to kill everybody'. The song just came out really powerfully ... I thought, 'Wow, this feels like Green Day.'

''A lot of my songs come from... not really anger, but anxiety. And feeling lost in the whole game.''

And the 'Wake me Up When September Ends' hitmaker has revealed ''searching for some kind of justice'' is ''ingrained'' into him and his fellow band members, which include Billie, bassist Mike Dint and Tré Cool.

He explained: ''I don't know how to get people fired up, [but] searching for some kind of justice in the world is ingrained into Green Day ... the only thing I would say to a young person is: look for the truth and find your own.''

Meanwhile, the California-born star has admitted he is ''confused'' and anxious about the forthcoming Presidential election on Tuesday (08.11.16).

He said: ''I'm just confused. I have anxiety about the whole thing. You wake up every morning and think, what now? What stupid thing's going to be said?

''I just think it's been mass manipulation.''

For the full interview pick up your free copy of NME magazine on Friday (04.11.16).