Sunday's incident took place on North 5th Street, near Lehigh Avenue, during what police described as a street party that takes place after the annual parade.
The department had no immediate comment on the video, which depicts a police officer hitting the woman while she is walking away from a group of officers. The officer apparently thought the woman threw beer at police.
City Councilwoman Maria Quinones Sanchez, a central organizer of the parade, said she spoke with Police Commissioner Charles H. Ramsey this morning, and that Ramsey was particularly upset because the incident involved a commanding officer.
"He was very concerned," Sanchez said. She noted that this year's parade theme was "The Puerto Rican Woman."
The lieutenant will be assigned to desk duty while the incident is investigated, police said.
Sanchez said she had met with police commanders before the parade in the hope of avoiding conflicts between police and paradegoers.
"It's unfortunate that this happened because we just talked about it before the parade," said Sanchez.
The woman, who is not identified, is shown falling to the ground, her face bloodied. In the seconds before the punch, the woman had been walking around a group of people and police officers. Someone near her in the crowd can be seen throwing some liquid into the air, toward the officers. (View the video here: www.bit.ly/Pnrjwe.)
It appears in the video that she had sprayed silly string from a can.
The woman was taken into custody and issued a citation for disorderly conduct, police said, then released.
Contact Allison Steele at 215-854-2641 or firstname.lastname@example.org