Tom Hardy struggled to film fight scenes for the new Batman movie because he worried he'd attack extras by mistake.
The British actor plays violent villain Bane, opposite Christian Bale's Caped Crusader, in the next installment of the superhero franchise, The Dark Knight Rises.
In one scene, Tom Hardy was required to beat up seven cops from a crowd of policemen - but he found it tricky to identify which actors were the stunt fighters.
He tells Britain's Empire magazine, "When you're training in a rehearsal room you go, 'Okay, I have a contact with seven people'. This guy I chin, this one I slip and I punch, this one I pick up and suplex, this guy I kick in the face, and this one, he stops a hammer with his head. And then I meet Batman.
"That's all alright in a rehearsal room, but then you add 1,000 people that are all dressed the same as the seven you're supposed to hit - because they're all police officers - and I don't know where my police officers are. But the stuntmaster's like, 'Don't worry. They will find you'.''
Opening up about his character, Tom Hardy adds, "He's brutal. He's a big dude who's incredibly clinical, in the fact that he has a result-based and orientated fighting style. Anything from small joint manipulation to crushing skulls, crushing rib cages, stamping on shins and knees and necks and collarbones and snapping heads off and tearing his fists through chests, ripping out spinal columns. It's anything he can get away with."