PHILADELPHIA — Philadelphia’s archbishop called it a “senseless act of aggression” after a woman who had finished a reading at a Catholic church was punched as she left the altar.

The attack took place Sunday during the 11 a.m. Mass which was streamed on Facebook Live from the Cathedral Basilica of Saints Peter and Paul.

Video showed the lector leaving the altar when a woman punched her.

“The lector who was assaulted received immediate attention and assistance from cathedral staff members off camera,” Archbishop Nelson Perez wrote on Facebook. She did not require medical attention, he said.

The suspect was not detained.

“Such behavior is unacceptable at all times, especially within the confines of a church building and during the celebration of the Holy Mass,” Perez said. He assured parishioners that security plans are in place at the cathedral.

The archdiocese was working with police.