What to do with other pets?

Hi everybody, I need an advice; Every evening I took my cocker spaniel for a walk/run at the park, more people is there with their dogs too, but some people don't control their dogs and they just go where me and my dog are walking/running, and I don't like that, most of the time when they are getting closer I said that I have to go maybe they get mad but what else can I do? or I'm being mean? should I stop and talk to them while their dogs keeps sniffing my dog? what should I say to them without being rude? I hope somebody would give me a good advice. Thank you.