You don't fire at these ships to stop them nor do you force a tow, you either bring the boat to a stop with tactical maneuvers or you simply tail the ship, they can't outrun you they can't loose you, this isn't a car chase, they no they are caught it's only a matter of time. The main factor in all this is it requires effort, which your government/coastguard wasnt prepared to do.
What you don't do to scared vulnerable people to get them to stop, is start shooting at them.