London, Mar 7 (IANS): Facebook has shut its three London offices till Monday after an employee was diagnosed with COVID-19.

The social networking giant told nearly 3,000 employees here to work from home after an employee, who was based in Singapore and visited the London offices between February 24-26, was diagnosed with the new coronavirus, Sky News reported on Friday.

Facebook said it would deep clean the premises before opening the offices.

"An employee based in our Singapore office who has been diagnosed with COVID-19 visited our London offices 24-26 February 2020.

"We are therefore closing our London offices until Monday for deep cleaning and employees are working from home until then," the company said in a statement.

There have been 163 cases of coronavirus in the UK.

Facebook has also recommended all its Bay Area employees in the US to work from home. The latest precautions come after San Francisco announced its first two coronavirus cases on Thursday.

Facebook has also shut its Seattle office until Monday after one of its contractors was confirmed to be infected with the virus.

The infected contractor was last in the Facebook office on February 21.

King County health officials said all Facebook sites should work from home until March 31.