Two police officers were attacked during an Occupy San Francisco march Saturday, police said.
Police spokesman Carlos Manfredi said officers were attempting to hold the line and keep protesters out of an intersection when a woman came from the crowd and slashed an officer's hand with a pen knife or razor blade, disappearing before he realized he'd been cut.
In a second incident in the same location, police said a man then came out of the crowd and grabbed an officer's radio, and when the officer chased him another male protester shoved the officer, tearing his uniform and leaving him with a bleeding laceration on his face.
Police did not know if that protester had a weapon or if the cut came during the struggle.
The attackers could not be found and no one was arrested.
Both officers were treated at the scene and released.
The Associated Press contributed to this report.