The latest COVID-19 outbreak in Sanya, Hainan province, is continuing to evolve at a high level, with 480 new confirmed cases and 774 asymptomatic infections registered on Wednesday, officials said at a news conference on Thursday.

With support from testing teams gathering around the country, nucleic acid test tubes were consumed rapidly, leading to a jump in daily confirmed cases and asymptomatic infections on Wednesday, said Jin Yuming, chief expert with the Hainan Center for Disease Control and Prevention.

He called on the public not to panic about the new figure and to continue actively cooperating with various epidemic prevention and control measures.

He said Sanya is building more makeshift hospitals and hotels to take in all infected people who are isolated at home in high-risk areas. Additional medical staff will be sent to makeshift hospitals to help diagnose cases.

As of 4 am on Thursday, Sanya had sent 2,156 tourists stranded by the island's latest outbreak back home to Xi'an, Chengdu and Shanghai, said Sheng Yongjun, executive vice mayor of Sanya. The epidemic left around 80,000 tourists stuck in the popular resort city.

More return journey arrangements are being made for tourists who pass health checks. A system for handling applications for return tickets was up and running on Wednesday, local officials said.

Instead of staying at hotels and waiting, many stranded tourists have volunteered to join local anti-epidemic efforts.

Tao Kun, an orthopedic physician from Shanghai, was one of the volunteers who offered a helping hand.

"This trip to Hainan was unforgettable,'' he was quoted as saying by The Paper on Thursday.

Tao and his family had a happy weeklong holiday, with their child learning how to snorkel and surf. The return journey was interrupted at the Sanya airport on Saturday when the city imposed a temporary lockdown to cope with the new COVID-19 outbreak.

Together with other tourists stranded at the airport, the Tao family was transferred and settled into a hotel later that day. Tao said he was grateful for the arrangements made by the Sanya government.

"I have experienced the epidemic in Shanghai and know the importance of prevention. Keeping tourists first in isolation for observation in Sanya is the best way to minimize the impact and reduce the risk of it spreading into other cities in China," Tao said.

As of Wednesday, Hainan had registered 2,126 confirmed cases and 1,644 asymptomatic ones since the first case was reported in Sanya on Aug 1. The coastal city alone logged 1,690 of the confirmed cases and 1,504 of the asymptomatic infections, the Hainan Health Commission said.