POLICE YESTERDAY continued to investigate an alleged rape that occurred Saturday night inside an Occupy Philly tent.

"There was sexual activity," police spokesman Lt. Ray Evers said last night. "We're not sure if it was consensual or not."

Evers said the Special Victims Unit and the District Attorney's Office will review surveillance tape - from City Hall, SEPTA and private area cameras - to help determine what happened.

A 25-year-old woman from Atlantic City reported that she was raped about 7:45 p.m. Saturday; she called 9-1-1 on a pay phone near City Hall.

Within 20 minutes, police arrested the suspect, a 50-year-old man with addresses in Michigan and Philadelphia, Evers said.

6ABC said the man had been arrested in a string of robberies in Michigan. Evers said the man "has a prior record in Michigan," but wouldn't elaborate. He said that the man was released early yesterday morning but that police know who he is and how to find him, if needed.

The alleged sexual assault occurred in a green tent, with a blue tarp underneath, near the northwest corner of City Hall.

The tent is owned by the group Fight for Philly, a coalition advocating for good jobs, but the woman who reported the rape is not a member of the group, said Jessica Burgan, the coalition's communications director.

The coalition uses the tent during the daytime. Burgan said coalition staffers don't know the woman or the man who was arrested.

Alyce Bowling Ehrmann, 71, of Northeast Philadelphia, who has a tent nearby, said she heard a woman screaming Saturday night, "but there were so many screams, one doesn't know if it's in joy [from sex] or in pain."

She said she didn't know if the screams were coming from that tent, or just from that direction.

Patrick DeWit, 22, of South Philly, said he didn't believe that the man arrested Saturday was the same man whose photo has been posted on fliers around Occupy Philly alerting people to a possible sex offender, who has reportedly groped and harassed women.

Evers last night said he did not know if it was the same man.