Police said officers were injured on Friday as they tried to break up a fight between two families and on Saturday as they pursued an assault suspect.
In the first incident, officers responding around 9 a.m. Friday to a report of a dispute between neighbors in the 1600 block of Sunnydale Avenue found eight people from two different families involved in a fight.
When the officers tried to intervene and stop the fight, two combatants allegedly sprayed two officers with a liquid chemical. Both officers experienced minor burns and temporary vision loss as a result, police said.
Additional police officers arrived and ultimately broke up the fight. The two injured officers were treated at the scene, and Regina Cole, 29, and Tyresha Blake, 23, were arrested on suspicion of assault with a caustic chemical, police said.
In the second incident, around 9:15 p.m. Saturday, officers responding to a report of an assault, possibly involving a knife, in the Haight-Ashbury neighborhood, near Waller and Clayton streets, arrived after the assailant departed.
They soon spotted someone matching a witness's description. He fled, but officers caught up to him near Page and Ashbury streets and tackled him to the ground. During the struggle, police said, the man stabbed a police sergeant in the face with a sharp metal object and injured two other officers.
The sergeant was hospitalized and received eight stitches in one cheek, and Mike Anderson, 40, of San Francisco ultimately was arrested on suspicion of aggravated assault, assault on an officer and resisting arrest, police said.
"Recent attacks on San Francisco police officers over the weekend are unacceptable, and they merit our city's most aggressive response," Police Chief William Scott said in a statement. "Although arrests have been made in these violent assaults, I ask for individuals with information that could be helpful to our investigation and prosecution of these cases to contact our 24-hour tip line."
The tip line can be reached at (415) 575-4444 or by texting TIP411 and bringing the message with SFPD. Tipsters can remain anonymous.