Oh. Pike cichlid. I was just thinking pike/pickerel as in our natives, since this is a native forum. Aggression won't be a problem then. You might want to move them to another tank anyways, just to be safe. Natives don't really belong in tropical tanks, IMO. They're to good for that.
I swear my eyes are having issues. Killies in with cichlids will eventually spell disaster. The Pike Cichlid can get to be 8 to 10 inches long and it is a predator. A 2-4 inch killie has no chance. One night the lights go out, the next morning, no more killies. Have them in their own tank, much safer.