Shanghai on Thursday expanded the list of countries from which travellers have to undergo a 14-day quarantine to 24 countries

China and the epicentre of its coronavirus outbreak, Wuhan city, have reported no new domestic transmissions for the first time, raising hopes that strict containment efforts to stop the spread of the virus are working.

Wuhan, locked down since Jan. 23, is currently the only city in Hubei province still designated "high-risk" and subject to strict travel bans, even as restrictions across the rest of the country have loosened in recent weeks.

The city relaxed quarantine rules slightly on Thursday, allowing people to walk in their compounds rather than staying confined to living quarters, state-run CCTV reported.

If no new case is reported for 14 consecutive days, the lockdown could gradually be lifted, the China Daily newspaper said, citing an epidemiologist.

"We expect new cases will cease to appear in mid or late March," Li Lanjuan, director of China's State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, told the newspaper.

The number of daily new infections in mainland China fell below 100 for the first time on March 6. On Thursday, there were 34 cases, up from 13 a day earlier. All of Thursday's cases involved travellers from abroad.

Total infections in mainland China stood at 80,928, with the death toll at 3,245 by Wednesday, up to eight from a day before. Wuhan accounted for six of the eight new deaths in Hubei.

No new infections have been reported for 14 days in the rest of Hubei, where authorities said on Thursday they would allow entry on certain conditions to people from other provinces.

China's recent efforts to fight the epidemic have increasingly focused on inbound travellers, amid concern about the second wave of infections from overseas.

New imported coronavirus infections hit a record of 21 in Beijing, data showed on Thursday, piling pressure on authorities to screen out infected passengers and isolate suspected cases.

"A single spark can start a prairie fire," state-backed China Daily wrote in an editorial.

On Wednesday, Beijing recorded 21 new infections from abroad, mostly in travellers from Britain and Spain.

Since last week, Beijing airport has set aside a special zone for international flights, with health checks required for all disembarking passengers. Non-transit travellers are sent to designated sites for a compulsory 14-day quarantine.

Beijing has halted self-quarantine for overseas arrivals, which had previously been allowed, according to state media.

China's aviation regulator said on Thursday it would divert some international flights bound for Beijing to other cities. The Global Times said China's aviation authority had appointed a team of 12 airport firms to help.

Such reports suggest the capital may have reached its limit in screening incoming visitors, a China Daily editorial said.

The southern province of Guangdong reported nine new imported cases, while the financial hub of Shanghai saw two new infections from overseas.

Shanghai on Thursday expanded the list of countries from which travellers have to undergo a 14-day quarantine to 24 countries, eight more than previously.

From Thursday, those entering Guangdong after visiting countries with high infection rates will be quarantined for 14 days at home or at a centralized medical centre, the official Xinhua news agency said. The far western region of Xinjiang adopted similar measures, Xinhua said.

China's eastern provinces of Shandong and Anhui, its southwestern city of Chongqing and Wuhan earlier said they would require all overseas arrivals to spend 14 days in quarantine.

China tentatively plans to hold late in April or early in May its annual gathering of parliament, two people involved in preparations told Reuters, after a delay, caused by the outbreak, from the initial date of early March.