One scene involves angry protestors. They can be seen throwing and hitting a truck with bats or 2x4s, in which several people are on board. No blood is seen.
A man can be seen injured, and being carried through the plant by two workers. A significant amount of blood is seen on the right side of his body.
Workers and protestors clash in one scene. They beat each other up, and blood is seen particularly on their faces. This fight scene lasts for several minutes.
A man fires warning shots with a shotgun. No one is injured, nor killed.
A woman slaps a man in the face.
Mel Gibson and Sissy Spacek are in a constant state of peril them fighting back a river and a bank, but there is very little blood. The movie is pretty intense though.