How I almost dealt with it ...
I restarted the mission and actually was able to get through the first batch of civilians without hurting any of them, all the while taking out the occasional raider among them. The ones on the roof were no problem to avoid, but there's one guy who's on the ground and chases you through the old town hall. I managed to sneak away from him after throwing the switch in front of the hall, but when I started shooting at the next batch of raiders he heard it and came running. At one point I lured him off to a secluded area of the map with one character and punched him until I got the 'K.O.' result. Hooray! My problems were solved - and no civilians were to die. Raiders, raiders, more raiders ... oh, crap! A whole *new* batch of civilians appeared with attack dogs mixed in, no less. They charged up en masse, throwing bombs and rocks and punching like mad.
At this point I just lost all patience and went back to aggressive sentry mode. I even went back to the town hall and finished off anybody who dared to continue hostilities (which was, of course, all of them).
I, too, think it would've been neat to drive them off by firing into the air ... but, despite all their protestations, the fact is that they were doing their damndest to kill me. Their damndest just wasn't very good.
They just pushed me a little too far.
Zombra