British actress Cara Delevingne says she felt like she was losing her "f***ing mind" while filming for director David Ayer's "Suicide Squad".

The 23-year-old, who stars as Enchantress in the much-anticipated new comic book movie, has revealed she fantasised about killing people in "demonic" moments during shooting, reports femalefirst.co.uk. 

"I tried to imagine the darkest s**t for a long time, like seeing people crumble and their skin melt in front of me or making people implode and trying to use my imagination in dark ways," Delevingne told The Sun newspaper. 

"I remember seeing a guy behind a bar cutting up a cucumber then seeing him cut all the way up his hand and I thought, 'I'm losing my f***ing mind'," she added