BEIJING, Oct. 21 (AFP) -- Authorities in China cancelled hundreds of flights, closed schools and ramped up mass testing on Thursday (Oct 21) to try and stamp out a new COVID-19 outbreak linked to a group of tourists.

Domestic outbreaks have largely been eliminated, but as China logged a fifth straight day of new cases - mostly in northern and northwestern areas - authorities beefed up coronavirus controls.

The latest outbreak was linked to an elderly couple who were in a group of several tourists. They started in Shanghai before flying to Xi'an, Gansu province and Inner Mongolia.

Dozens of cases have since been linked to their travel, with close contacts in at least five provinces and regions, including the capital Beijing.

In response, local governments have rolled out mass testing and closed scenic spots and tourist sites, schools and entertainment venues in affected areas, and also imposed targeted lockdowns of housing compounds.

Some regions including Lanzhou - a city of some 4 million people in northwestern China - have told residents not to leave unless necessary.Those who need to leave must present a negative COVID-19 test.