Facebook announced on Friday that the London office and part of the Singapore base would be closed for "deep cleaning" after being diagnosed with a coronavirus worker in the Asian city-state.
An employee of the US technology giant's Marina One office in Singapore was diagnosed with COVID-19 on Friday, a spokesman for AFP said.
"We immediately closed the affected areas for thorough cleaning and advised employees in the affected area to work from home by March 13," he said in an emailed statement.
The infected employee also visited Facebook's London offices between February 24 and 26.
"We are therefore closing our London offices until Monday for thorough cleaning and the staff will be working from home by then," said the spokesman.
The company said it contacted people who had direct contact with the infected person and asked them to isolate themselves and monitor possible symptoms.
Facebook has closed its office in Shanghai until further notice, while employees in Italy and South Korea have been asked to work from home.
In addition, employees in San Francisco Bay were "strongly recommended" to work from home on Friday.
According to an AFP record, coronavirus has infected more than 100,000 people worldwide in 91 countries, while more than 3,400 people have died.
A total of 163 people have now tested positive for the virus in the UK, and two people have died, health officials said on Friday.