Facebook Inc and Alphabet Inc’s Google on Thursday recommended their San Francisco Bay area employees work from home to minimize the risk of spreading coronavirus.

Facebook said it is “strongly recommending that all Bay area employees and contingent staff work from home starting Friday.”

The decision is “based on the guidance from Santa Clara County on Thursday”, Anthony Harrison, Facebook spokesperson, said in an emailed statement to Reuters.

Employees and contractors involved in the site’s safety and security will continue to work on site, while all Bay Area events will remain canceled, according to the statement.

Separately, Google has offered a work-from-home option to employees in Bay Area offices, a spokesperson told Reuters in an emailed statement.

Meanwhile, Microsoft Corp confirmed early on Friday that two of its employees have been diagnosed with COVID-19.

“A Microsoft employee and a LinkedIn employee, both in Puget Sound, are among those diagnosed with COVID-19,” the company said in a statement.

Coronavirus test kits were delivered on Thursday to an ocean liner at sea, as it was barred from returning to port in San Francisco after at least 35 people aboard the vessel developed flu-like symptoms, which has been linked to two other confirmed cases of COVID-19.