Early on Sunday police battled with protestors in what has become one of Berlin’s hot spots for disturbances on May Day, the Boxhagener Platz in the Friedrichshain district.Over one thousand people had gathered for an authorised concert. When it finished some of the crowd reportedly started throwing bottles and other objects. The police moved in and arrested 31 people. There were a number of injuries. Authorities said disturbances had been mild so far compared with last year. Police said there would be “significantly fewer” law enforcers on the streets this year.