The world is nearing the “tipping point” at which the coronavirus outbreak will become an uncontrollable pandemic, experts have warned.

Some 80,000 people have now been infected globally and more than 2,600 have died, mostly in China, according to a tracking database run by Johns Hopkins University.

At the weekend England’s chief medical officer confirmed that four people brought back to the UK from the Diamond Princess cruise ship have tested positive, bringing the British total to 13 cases. The quartet, along with 28 others, are now in quarantine on Merseyside.

Professor Paul Hunter, of the University of East Anglia, said a recent surge of cases outside China was “extremely concerning”. Infections in South Korea, Japan and Iran were causes for concern while said a cluster of cases in Italy was “a big worry for Europe”, he added.

Prof Hunter said: “The director-general of the World Health Organisation (WHO) has recently spoken of a narrowing of the window of opportunity to control the current epidemic. The tipping point after which our ability to prevent a global pandemic seems a lot closer after the past 24 hours.”

Ukrainian protesters attack bus carrying coronavirus evacuees Show all 9 1 /9 Ukrainian protesters attack bus carrying coronavirus evacuees Ukrainian protesters attack bus carrying coronavirus evacuees Ukrainian law enforcement officers clear the way as demonstrators block a road during a protest against the arrival of evacuees from China REUTERS Ukrainian protesters attack bus carrying coronavirus evacuees Buses carrying evacuees from coronavirus-hit China drive to a medical facility as law enforcement officers clear the way from protesters AFP via Getty Images Ukrainian protesters attack bus carrying coronavirus evacuees Ukrainian firefighters clear the way after protesters attempt to stop the arrival of evacuees from China REUTERS Ukrainian protesters attack bus carrying coronavirus evacuees A demonstrator throws a stone towards a police van during a protest against the arrival of a plane carrying evacuees from China REUTERS Ukrainian protesters attack bus carrying coronavirus evacuees A Ukrainian riot police officer detains a protester, who planned to stop buses carrying passengers evacuated from China AP Ukrainian protesters attack bus carrying coronavirus evacuees Demonstrators set fire and erect a barricade as they protest the arrival of a plane carrying evacuees from China REUTERS Ukrainian protesters attack bus carrying coronavirus evacuees Ukrainian riot police run to push protesters outside Novi Sarzhany, Ukraine AP Ukrainian protesters attack bus carrying coronavirus evacuees Protesters help an injured demonstrator, who attempted to stop buses carrying China evacuees AP Ukrainian protesters attack bus carrying coronavirus evacuees Protesters speak to Ukrainian riot police blocking the road outside Novi Sarzhany AP

And Dr Bharat Pankhania, a clinical lecturer at Exeter University, told The Daily Telegraph: “It is clear that all the important ingredients for a pandemic are now present. It’s better to be honest and say it.”

The warnings came after the WHO chief, Tedros Adhanom Ghebreyesus, told a meeting of African health ministers of his fears about the emergence of cases that had shown ”no clear epidemiological link, such as travel history to China or contact with a confirmed case” – especially in Iran.

On Monday Kuwait announced that it had detected its first three cases of coronavirus in people who had travelled from Iran, including a Saudi Arabian citizen. Bahrain also announced its first case, with the infected person again having travelled from Iran.

However, China has relaxed some restrictions on its citizens’ movements, including in Beijing, after rates of new infections fell. While admitting the outbreak remained “severe and complex”, premier Xi Jingping urged businesses to return to normal working patterns.

Guizhou, Yunnan, Shanxi and Guangdong provinces lowered their coronavirus emergency response measures from the highest level, joining the provinces of Gansu and Liaoning in easing travel restrictions.

The Johns Hopkins University tracking tool showed that about 25,000 people around the world had recovered from coronavirus infections.

Research released on Monday suggested that one-third of Britons would consider ceasing to travel overseas if the outbreak persisted, putting some £17bn of holiday spending on hold.