COPENHAGEN  In the first major police action since United Nations climate talks began here on Monday, Danish law enforcement officers fanned out across the city Friday morning in anticipation of protests at various corporate targets, including McDonald’s, a Danish industry association headquarters and the shipping giant Maersk.

Several arrests have already been made, according to the police, as protesters continued to move out from a meeting point in the city center.

Roughly 250 protesters descended on Nytorv Square near the Copenhagen city courthouse at 10 a.m.  many apparently responding to a directive issued online earlier this month at notyourbusiness.hacklab.dk. Photocopies of a map detailing 15 potential targets, along with instructions, could be seen circulating among the gathered crowd.

A 7-Eleven convenience store facing the square had boarded up its windows in anticipation of trouble.