A growing number of imported coronavirus cases in China risked fanning a second wave of infections when domestic transmissions had “basically been stopped”, a senior health official said on Sunday, while eased travel curbs may also add to domestic risks.

China, where the disease first emerged in the central city of Wuhan, had an accumulated total of 693 cases entering from overseas, which meant “the possibility of a new round of infections remains relatively big”, Mi Feng, spokesman for the National Health Commission (NHC), said.

Nearly a quarter of those came from arrivals in Beijing. “Beijing, the capital, still bears the brunt of the risks,” said Xu Hejian, spokesman for the Beijing government. “There’s no reason to lay back and relax yet. It’s not a time when we can say everything is going well.”

Most of those imported cases have involved Chinese returning home from abroad. A total of 3,300 people have now died in mainland China, with a reported 81,439 infections.

In the past seven days, China has reported 313 imported cases of coronavirus but only six confirmed cases of domestic transmission, NHC’s data showed. There were 45 new coronavirus cases reported in the mainland on Saturday, down from 54 on the previous day, with all but one involving travellers from overseas.

Airlines have been ordered to sharply cut international flights from Sunday.

Five more people died on Saturday, all of them in Wuhan, the capital of Hubei province. It has reported only one new case in the past 10 days.

More than 7,000 have returned to Beijing from Hubei by charted trains or private cars, Mao Jun, a Beijing government official, said on Sunday.

As travel restrictions are rolled back, concerns about asymptomatic cases have intensified. Gansu in northwestern China reported a new case on Sunday of a traveller from Hubei who drove back on a health code declaring the person free of virus.