We see many people attacked by piranhas and men, women and children scream: we see blood covering many people, we see a piranha biting a young woman's neck and blood spouts from the wound, a man enters the water and shoots piranhas with a machine gun, and one shot hits a young man, knocking him backwards as pieces of exploding fish are seen in the water and blood fills a pool; we hear children screaming, a man rushes to help a shouting child, knocking a man over and pushing another man into the water, dead bodies are seen on the side of the pool and floating on top of the water, a man is seen missing an arm, a young man has the back half of a piranha literally sticking up his ass (headfirst, blood covers his buttocks) and another young man helps pull the piranha out of his ass as he screams (several of the above and definitely the last instance listed are played for comedy).
A piranha appears to rip through a young woman's body: she seizes on a bed as a young man thrusts above her, engaged in active sex, we see blood spray as the young man pulls away from the young woman, a piranha is seen on his genitals, and the young man uses a large butcher knife to chop off his genitals (we see a spray of blood); the young woman wakes, blood is covering her and the room and she walks over to the fish, lying in a pool of blood, steps on it and it spits out the young man's genitals. This is extremely horrific and graphic.
As a television reporter narrates, we see a short flashback of the "Lake Victoria Massacre" from the first movie. Blood fill the water of a crowded lake; young men and women struggle to climb onto a stage, leaving behind bloody handprints as some of them are dragged under the water; we see boats and swimming floats covered in blood and bloody people.
A young man grabs the partially eaten body of a young woman from the water, we see blood and gore coming from her body, and she appears to have been decapitated; many bodies are seen covering the ground and floating in the water, including partially eaten bodies.
We see the dead body of a young woman as a piranha snaps at her finger and swims away (the body appears covered in bite marks).
A piranha leaps at two young women who angrily smash it to death causing blood to spray over them.
A young woman is dragged out of the water and is unharmed except from a small bite on her ankle (we later see the cut look slightly gangrenous).
A man has a flashback of himself using a boat motor to kill many piranhas; blood fills the water.
A young woman swims in blood-filled water and we see disembodied limbs zoom past her, the young woman begs a young man for help and she goes underwater.
Seconds before a young woman is attacked by a fully-grown piranha, a young man throws a spear through its head.
We see blood pooling in the water under a woman on a raft and seconds later she screams.