Britain strike and anarchists

Britain strike: Britain's government workers in mass strike - latimes.com: "The demonstration here in the capital was mostly a peaceful affair, although a few scuffles broke out between police and suspected anarchists in hooded shirts."

What could be less anarchic than public sector unions? One would expect them to be working with the police to minimize the impact of the strike. Not really, because we all know that most of the Anarchists are just malcontents looking for the next focal point where to party, destroy stuff, and hopefully get laid.