Experts from the United Nations are on their way to Africa to try to find out why four gorillas have been killed.
The bodies of the mountain gorillas were discovered by keepers at a national park where they lived in the Democratic Republic of Congo.
It's a mystery why the three females and one male gorilla - all thought to be from one family - were killed.
Since January, seven of the large apes in the area have been shot dead and experts want to put a stop to it.
They don't think hunters are to blame because the bodies of the animals were left behind.
The four animals belonged to a group of 12 gorillas, known to researchers as the Rugendo family, which are often visited by tourists.
There are only around 700 mountain gorillas alive in the world, and more than half of them live in the national park in the Democratic Republic of Congo.