Well, like Mistic said above, and cichlid tank should have a lot of hiding spots in it. Lots and lots of caves. Cichlids are very aggresive, especially the ones you have. If you can, get tons of rock and start stacking it and making caves and holes for the cichlids to hide in. Another idea is to add more fish so the aggrestion goes down, but with the fish you have and the size they will get, I do not suggest adding more fish.
Only thing I can think of is just rescape your tank and add tons of hiding spots.