A chartered Boeing 747 touched down at the March Air Reserve Base in Riverside on Wednesday morning, where it was met on the tarmac by emergency vehicles and three buses, as personnel in biological hazard suits stood by.

Almost 200 US citizens evacuated from the Chinese city at the heart of the deadly coronavirus epidemic landed at a military base in California on Wednesday, where officials declared them free of symptoms.

But they will remain isolated in their quarters for a period of up to 72 hours while they are monitored, and have been asked to submit samples to test for the presence of the 2019 Novel Coronavirus, Nancy Messonnier of the Centers for Disease Control and Prevention (CDC) said.

A chartered Boeing 747 touched down at the March Air Reserve Base in Riverside on Wednesday morning, where it was met on the tarmac by emergency vehicles and three buses, as personnel in biological hazard suits stood by.

Messonnier said the 195 passengers "cheered loudly" when they first touched down on US soil in Anchorage, Alaska for a fueling stop.

The epidemic has killed more than 130 people and spread around the world since it first emerged in a live food market in Wuhan in December.

Alyssa Farah, a spokeswoman for the Department of Defense, said the group included State Department employees and their dependents.

She added that the evacuees "will not have access to any base location other than their assigned housing."

"The Department's primary responsibility at this time is the safety of our force, our families, and our base communities."

The maximum incubation period of the virus -- the gap between infection and the appearance of symptoms -- is thought to be two weeks, though in some cases symptoms have emerged within a matter of days.

Nor is it fully clear whether transmission can occur if a patient is not yet showing symptoms.

The US has so far confirmed five cases of the 2019 Novel Coronavirus with another 95 under investigation, with officials warning that more cases are likely.