Facebook has become the first big US firm to tell staff to avoid travelling to China, as the death toll from the coronavirus rises.
The tech giant said it was acting “out of an abundance of caution” to protect its employees. Other global companies have introduced travel restrictions and car makers are taking staff out of the country.
More than 100 people have died of the disease, and confirmed cases have risen above 4,500.
China has imposed further restrictions on travel in and out of Hubei province, where the virus originated, as it tries to curb the spread of the virus and transport links in and out of the capital Wuhan is effectively in lockdown.
Some domestic firms have responded by extending the Chinese New Year holiday and asking staff to work from home.
Facebook, which has a division in China selling products such as Oculus virtual reality headsets, has asked employees to halt non-essential travel to mainland China and told employees who had travelled there to work from home.
“We have taken steps to protect the health and safety of our employees,” a spokesman for the social media giant said.
The US government has asked Americans to “reconsider” planned visits to China and is advising against travel to Hubei province. Washington has also said it plans to fly consular staff and US citizens out of Wuhan. Governments of several countries are considering helping their nationals to leave the city.
South Korean companies are also taking steps to protect their employees from the potential infection.
Home appliances company LG has put a complete ban on travel to China and has advised employees on business trips in the country to return home as quickly as possible. Chipmaker SK Hynix has urged staff to avoid all non-essential travel to China.