NEW YORK — Animal activists say they are going directly after the designers who do fur, and they started this week with Calvin Klein.

Ironically, Klein does not currently have a fur license. However, he did have one for 17 years with Alixandre Furs, a deal that ended in December.

Nevertheless, about 15 members of People for the Ethical Treatment of Animals invaded the headquarters of Calvin Klein Inc., at 205 West 39th St., just before noon on Tuesday. According to a Klein spokesman, they hurdled the receptionist’s desk and roamed the Klein offices shouting, “Compassion is the fashion” and “Fur shame.” One protester spray-painted over the Klein logo in the office lobby.

Seven PETA demonstrators who refused to leave the premises were arrested, police said. Six were charged with criminal mischief, felony and criminal trespass. The seventh was charged with assault. The six spent the night in jail and were released Wednesday morning.

“We intend to turn up the pressure on Calvin and all other designers who still use fur, before the spring fur shows,” said Dan Mathews, director of special projects for PETA, who was present at the protest. “The occupation of Vogue this past fall set the tone for the escalation.”

Mathews noted that he was not aware that Klein’s license had expired, and said someone within the designer’s office confirmed that he was still working with fur in the last few weeks.

The Klein spokeswoman noted that all signs of the event had been removed by Wednesday morning, and it was “back to business as usual.”

“We understand and appreciate the deeply held views of many people on this issue and are always willing to participate in a free and open dialogue on the subject,” said Klein Wednesday, in a statement.

“However, activities such as yesterday’s confrontation step over the line of legitimate protest and make it impossible to have a true discussion of the issues.”