A group of 10 men attacked two other men Sunday afternoon in a brawl just one block from San Francisco City Hall, authorities said.
One of the victims reported the incident to the police on Tuesday, the San Francisco Police Department said. The victim told investigators that the group of men approached him and his friend on Grove Street, threatened them and then assaulted him with a "metal weapon."
Bystanders helped separate the men, police said. It was not clear what sparked the alleged assault. No arrests have been made.
One victim was injured with non-life-threatening injuries and was taken to a hospital outside of the city by a friend, police said.
The incident contrasts with the apparent success of the new skate park at the nearby U.N. Plaza.
Local officials say crime and reckless behavior have diminished during the day since the park opened. For skaters, the new park symbolizes a dramatic change in how the local government treats them, as the sport had effectively been banned in the plaza before.