China reported 101 new coronavirus cases Wednesday, its highest single-day figure in three months, as gyms, bars and museums closed in infection hotspots.

Of the new cases, 98 were domestic infections, mostly in the northwestern region of Xinjiang, where a growing cluster first discovered earlier this month has prompted mass testing and restrictions.

China -- where the global outbreak first emerged -- had largely brought domestic transmission under control through targeted lockdowns, travel restrictions and testing. But sporadic regional outbreaks have illustrated the difficulty of keeping the virus at bay.

The last time it recorded so many new cases was April 13, when 108 infections were confirmed -- mostly imported.

Authorities have concentrated their attention on a cluster which emerged last week at a food processing plant in Dalian, in the northeastern province of Liaoning. Officials said workers there handled contaminated packaging of imported seafood.

Fifty-two cases have been confirmed in the major port city in the past week, of which 30 involved employees at the factory.

More than three million people have been tested in Dalian and Zhao Lian, head of the city's health commission, said Wednesday that enclosed public venues -- including libraries, gyms, bars, museums, restaurants and spas -- would be closed.

During an inspection tour to the city this week, Vice Premier Sun Chunlan urged local authorities to increase oversight of imported goods, as well as of any people leaving Dalian, state news agency Xinhua reported Tuesday.

"The task of prevention and control is still arduous, and there should be no slacking," Sun was quoted as saying.

Following a June outbreak in Beijing which infected more than 300 people, Dalian authorities are using a similar targeted approach to implement virus control measures on different districts of the city based on their risk levels.

In total, 84,060 people have been infected with coronavirus in China, of whom 482 remain hospitalised. There have been 4,634 related deaths, according to an official count.

Virus deaths surge in US
Coronavirus deaths in the United States surged to their highest level in months. The human toll of the disease surged to a level not seen since mid-May in the United States, the world's hardest-hit country, with nearly 1,600 deaths recorded in 24 hours, Johns Hopkins University reported on Tuesday.

Case numbers have been rising for weeks across swathes of the nation, leaving health authorities and leaders to watch nervously for a feared spike in fatalities.

President Donald Trump's effort to be re-elected in November has been dogged by a crisis that has already killed nearly 150,000 Americans and wreaked havoc on the world's biggest economy.

Twitter removed a video that Trump retweeted in which doctors made allegedly false claims about the pandemic, saying it was in violation of its "COVID-19 misinformation policy."

Earlier, Facebook had also withdrawn the video, which claimed masks and lockdowns were not necessary to counter the pandemic.

Resurgent virus outbreaks have forced nations around the world to step up measures against the contagion, leaving holiday tourism and event calenders in shambles.

- 'Rapidly and uncontrollably' -
Several countries have nonetheless imposed quarantines on people returning from Spain, including its biggest tourist market, Britain.

Spain's strict lockdown destroyed more than a million jobs during the second quarter of the year, the National Statistics Institute (INE) reported Tuesday -- mainly in tourism.

Germany, which has registered an average of 557 new cases a day over the past week, also tweaked its mask rules, saying they must be worn outdoors wherever social distancing was not possible.

"We must prevent that the virus once again spreads rapidly and uncontrollably," its disease control agency said Tuesday.

Iran suffered its worst day yet of the pandemic, reporting 235 new deaths on Tuesday, a record toll for a single day in the Middle East's hardest-hit country.

"The situation is worrying," health ministry spokeswoman Sima Sadat Lari said, with Tehran, the most populous province, hitting the highest category on the country's coronavirus risk scale.

Officials have made masks mandatory in enclosed public spaces and allowed Tehran and other hard-hit provinces reimpose restrictions progressively lifted since April to reopen Iran's sanctions-hit economy.

Lebanon also raised fears for its crisis-hit health sector after recording 175 cases on Saturday, its highest daily tally. 

On Tuesday, it announced a full lockdown July 30-August 3 over the Muslim holiday of Eid al-Adha, and limits on bar and restaurant capacity.

And in Colombia, President Ivan Duque announced an extension of lockdown measures until August 30, as the number of cases in the South American country continues to climb. Colombia has reported more than 9,000 COVID-19 deaths in nearly five months of the pandemic.