Those are not aiptasia. They are either a palythia or a zoanthid.
If a paly, you want to be extra careful if you remove them as some contain a toxin that can make you sick. Wear kitchen gloves or get full length glove, wear a dust mask and safety glasses.
Otherwise let them grow. Not harmful to the tank or it’s inhabitants.
If you want you could either move the other coral (not sure what it is, zoa or mushrooms?), or you could pull the rock and break it with a hammer and chisel so they won’t grow against each other.