BEIJING — Fifteen more COVID-19 cases have been reported in the southern Chinese province of Guangzhou, with a report saying the coronavirus variant in the latest outbreak is more transmissible than in previous clusters in the country.

The city of Guangdong has locked down neighborhoods and requires anyone wishing to leave the province to show a negative virus test taken within the past 72 hours.

Respected business magazine Caixin quotes the chief infectious disease specialist at the hospital in Guangzhou where the latest cases are being treated as saying the patients are carrying a heavier viral load than in past, making it easier to pass the virus to others.

Guangdong, which borders on Hong Kong, has reported around 50 cases as of Thursday.