San Francisco police said Wednesday that Stonestown Galleria was evacuated after officers responded to reports of a person making threats at the shopping center.

At about 11:40 a.m., officers were called to the mall, near Buckingham Way and Winston Drive, and were working with the property manager to investigate the threat, police spokesperson Ofc. Robert Rueca said in a statement. Stonestown Galleria is a shopping center near San Francisco State University.

The mall was evacuated, and traffic in the area was being rerouted during the investigation, police said. Rueca said additional SFPD resources, including the tactical team, K-9 units and the bomb squad, were searching the area and the buildings. Officers from San Francisco State University police and the San Francisco Sheriff’s Office were also assisting, he said.

Earlier Wednesday afternoon, San Francisco public safety officials issued an AlertSF advisory urging residents to avoid the area around 3251 20th Ave. because of police activity.

“Emergency crews are on scene. Expect traffic delays, consider alternate routes, and allow for additional travel time,” the alert said.

Dozens of people crowded outside the mall as a pair of helicopters circled overhead shortly after 2 p.m. Apichai Srisopa, 55, said he was shopping at Whole Foods when an announcement came over the intercom ordering customers to evacuate. Srisopa decamped to the parking lot, abandoning his full cart of groceries. 

“They said we could leave if we wanted to leave, but my stuff is in there, so I can’t really go home yet,” Srisopa said. 

Srisopa saw people leave the mall “in waves,” he said, as different stores cleared out. Jenna Seaman, who works in Whole Foods’ prepared foods section, said she and her coworkers followed fire-drill protocols after their manager asked them to evacuate the store. Seaman had spent more than 45 minutes sitting on a curb in the the parking lot, watching as officers blocked off the mall’s entrance and brought police dogs inside. 

Police did not release further details about the nature of the threats, and it was not immediately clear whether anyone had been injured.

The mall’s operator, GGP, declined to comment and referred inquiries to the San Francisco Police Department.