1:29 PM (Eve Batey): According to Alert SF, those streets have reopened.
The threat that closed them? According to the Chron, someone donated what resembled a cannon ball to the Salvation Army at 1500 Valencia St.
Police closed the area to remove to object more safely, they report.
12:18 PM: San Francisco police are asking people to stay away from part of the city's Mission District while a bomb squad investigates reports of a suspicious item in the area, a police spokesman said.
The department received a call at 10:27 a.m. reporting a "suspicious item" in the area of 26th Street and San Jose Avenue, police spokesman Albie Esparza said.
As of noon, a bomb squad was en route to the scene and occupants of nearby buildings were being evacuated as a precaution, Esparza said.
Several streets have been closed to facilitate the investigation, and police are asking people to steer clear of the area bounded by 25th and 26th streets and Guerrero Street and San Jose Avenue.