Authorities in China have cancelled hundreds of flights, closed schools and ramped up mass testing to try and stamp out a new Covid-19 outbreak linked to a group of tourists.

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, AFP reported.

Some regions including Lanzhou — a city of some four million people in northwestern China — have told residents not to leave unless necessary.

Airports in the affected regions have cancelled hundreds of flights, according to data from aviation tracker VariFlight.