My Ships Attack by - My Own Fortress as Pirates

[ashley26ph2003]

hi

I m using the latest patch AOD 1.05 by Dale
I try to play as Pirates
build fortress in my island
when my ships waiting to enter my settlement with fortress
My ships being fired by my Own fortress with cannons in it
Why should my own ships fired by my own fortress?

It says ships hit 12%
sunk etc

How to fix it?