Police in California said they nabbed seven suspects following a jewelry store heist this week in which nearly two dozen thieves ransacked the business and made off with $1 million in merchandise.

The San Ramon Police Department said Wednesday that those arrested range in age from 17 to 31 and all live in Oakland. None of their identities has been publicized.

Authorities believe Monday’s fast-moving, flash-mob robbery at Heller Jewelers in San Ramon, half an hour east of Oakland, was planned days in advance. Investigators suspect the same group is responsible for similar lootings throughout the Bay Area.

“When they went in, they basically took over the store,” Lt. Mike Pistello said, later adding, “This is not their first time doing something like this.”

Police said thieves swarmed the store and smashed the display cases with crowbars and pickaxes before bagging the jewelry.

The store’s security system automatically locked the front door during the raid, police said, which was a new feature after the business was robbed in 2023.

Officials said one of the suspects pulled a gun and shot out the glass door to escape. Authorities said at least two other people were armed.

The thieves darted into six cars parked in the valet area of the commercial strip and sped off. Police said officers gave chase initially, but backed off once speeds exceeded 100 mph due to public safety concerns.

San Ramon police said surveillance and drone footage, as well as videos from other shoppers and coordination with neighboring agencies, helped track down the seven suspects.

Police said they recovered two guns and some jewelry following the initial arrests. Many of the getaway vehicles were reported stolen.

Charges against the suspects were not shared by authorities.

• Matt Delaney can be reached at mdelaney@washingtontimes.com.