Antifa?

The news describes them as organized, dressed in black, wearing masks and some of them helmets, and here to rumble.

Successors to yester-year's anarchists?

Meanwhile, according to the MSNBC newsie on the ground, armed white militia were here early on and police, far from disarming them, checked them in and let them form up early in the day to provide security for rightist demonstrators.

I've no idea where they are now or what involvement they may have had in clashes, if any.

This image of some antifas is from Huffpo.