I dealt with this in Chile every day. When they'd attack me, I'd have no choice but to kick the shit out of them. I've already told the story and people gave me crap for being a dick, but when it's all you can do, it's all you can do.
Seriously, the best solution to this is to round them up an kill them all. They will breed, and get so big in numbers that there isn't enough food to scavenge and they start eating each other. I saw that with my own eyes. It's ridiculous.
They ought to get a task force, drive around in trucks, capture these things and put them all down. It's the only way to stop it from spreading and getting gross with dogs tearing each other up and spreading disease.