I personally have some female friends and I am very sure about
what is the level of interaction and the kind of platonic
relationships that I have with them.
As long as you can draw a clear line and have a clear frame of mind
about your interaction with them, I do not see why you can't have
good friends of the opposite gender.
It all boils down to your own maturity and ability to handle
people. If the other party mistakes your friendliness for something
more, try taking a step backwards and see the reaction. I am quite
sure they will get the signal too.