Philadelphia Mayor Michael Nutter said Sunday that he would increase police presence around the "Occupy Philadelphia" protest site after a woman was allegedly raped in a tent there.

Police were called to the encampment at City Hall just before 8:00pm Saturday after a woman claimed she was sexually assaulted in a tent by a man, ABC News reported.

The suspect was arrested almost immediately after the alleged assault. He reportedly traveled from out-of-state to join the protest, and has been arrested multiple times in connection with a string of armed robberies in Kalamazoo, Mich.

Nutter cited the alleged assault, as well as public health and safety concerns, as the reasons for the increase in uniformed police around the campsite.

"'Occupy Philadelphia' has changed, so we must change our relationship with them," he said.

He said conditions at the protest site were "unsanitary," and protesters were defying regulations by using cooking stoves, candles and lanterns.

"It is abundantly clear that 'Occupy Philadelphia' is in violation of the terms of its permit," Nutter said.

He stressed that despite the increased police presence, "We do not seek confrontation with 'Occupy Philadelphia.'"