Don't wait until an angry explosion to deal with anger. Kids need to learn coping skills at a calm time so that they can apply what they learn to angry times. You may want to talk about specific issues that anger your child and make a plan for what to do next time. Often role-playing the situation helps a child learn what to do. Watch media influence.
Kids see violence as a way of handling anger via television, movies and video games.
You can control this influence in several ways. First, screen what your child sees when possible. Set rules about appropriate TV and movie watching. Don't let your child watch endless hours of unsupervised television. Another powerful tool is to take advantage of the scenes you view together.