Several Chinese provinces and cities say they'll start giving COVID-19 vaccines to children as young as 3 after already fully vaccinating 76% of the population.

The expansion of its vaccination campaign comes as parts of China take new clampdown measures to try to stamp out small outbreaks.

China maintains a zero-tolerance policy toward the pandemic, using lockdowns, quarantines and compulsory testing to eliminate the virus.

Gansu, a northwestern province heavily dependent on tourism, closed all tourist sites Monday after finding new COVID-19 cases.

The spread of the delta variant by travelers is of particular concern ahead of the Beijing Olympics in February.