AGREE with socks peper or cs spray, you can get better than this though, and its somthing i have used alot whilst working in spain , GEL GAS, same as peper spray but comes out directional and in a stream , a bit like silly string.
this sticks to the fooker you aim at, where as peper spray is afected by the slightest of beezes.
warning if you get any of this on yourself, DO NOT ATEMPT TO WASH IT OFF, DO NOT.... all you will do is wash it deeper in to your skin pours.
just walk in to the wind as quik as you can away from the agro , and let your nose and eys stream DO NOT RUB