I suppose this depends on where you lve. Where I live, I know where everyuone lives, and I recognise their parents, so i would either hand out a kicking, or go and have a word with their parents. However, as with most of this country, you're probably in a city where you dont know them from jack.
If there, depending on how manythere were, I'd make a snap decision on how to get out and how likely cops were to intervene, and if i had agood chance of coming through, I'd knock the fucker to the floor and dish out a beating, no matter what would happen following. This is however the attitiude that gave me the beating of my life in Stepney Green..... so probably would advise running and live to own an AK47 or at least dream about it