(CNN) Nearly seven million people living in a wide swath of Northern California, including Silicon Valley, are being ordered to shelter in place starting at midnight Monday night as authorities try to stop the novel coronavirus from spreading.

Along with San Francisco, which previously announced its order, residents in San Mateo, Santa Clara, Marin, Alameda, and Contra Costa counties, as well as the city of Berkeley, are required to stay home, per an order from health officers of those jurisdictions.

The Bay Area order is the most draconian yet of measures being taken across the country to stem the virus' spread as the number of cases continues to rise.

"We must move aggressively and immediately," San Jose Mayor Sam Liccardo said at a news conference announcing the order. "The time for half measures is over. History will not forgive us for waiting an hour more."

Health services, grocery stores, gas stations, banks and food delivery services will remain open. Mass transit will stay open but is to be used only for travel to and from essential services.

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