In "Self-Defence Against Fresh Fruit," one of the Self-Defense students is shot by the teacher with a gun. (This movie only shows the first half of the sketch. The whole sketch, which was featured in Flying Circus, also includes the second student being squashed by a sixteen-ton weight and the other two students being attacked and presumably eaten by a tiger.)
People are shown being blown up from a distance.
Several people die from laughing at the world's funniest joke, and we see this being used in a war setting.
A cartoon shows a man cutting off his head. No blood, but the stump is visible.