Around 12 million people are affected by the new restrictions, adding to the tens of millions of people already quarantined in and around Wuhan, ground zero for 2019-nCoV.

The city of Taizhou, parts of Hangzhou -- including the district that is home to the headquarters of Chinese tech giant Alibaba -- and some of Ningbo will only allow one person per household to go outside every two days to buy necessities, city officials said.

Taizhou -- 850 kilometers from the epicenter in Hubei province -- will also suspend 95 train services into the city from Tuesday.

In addition, residential communities will only be allowed to use one entrance and residents must present ID each time they come or go, Taizhou's government said on its official WeChat account.

Landlords were also forbidden from renting property to people from "severely affected areas such as Hubei" if they have travelled to their hometowns recently, it added.

In the Hangzhou districts, additional measures included mandatory mask wearing and compulsory ID and temperature checks.

The latest restrictions follow similar measures announced Sunday in Wenzhou, which has a population of nine million people. 

The city has restricted the movement of residents, and closed roads.

Zhejiang -- the eastern province in which these cities sit -- has confirmed 829 cases, the highest number outside central Hubei province, the epicenter of the outbreak and where more than 50 million people are under lockdown.

Other provinces have restricted travel to try to stop the virus spreading, with several, including Guangdong and Sichuan, making it compulsory to wear masks in public.

Nationwide, more than 20,000 people have been infected by the new virus, with 425 now known to have died.