The Olympics host city Tokyo, as well as Thailand and Malaysia, announced record COVID-19 infections on Saturday, mostly driven by the highly transmissible Delta variant of the disease.
Cases surged in Sydney as well, where police cordoned off the central business district to prevent a protest against a strict lockdown that will last until the end of August.
Police in Sydney closed train stations, banned taxis from dropping passengers off downtown and deployed 1,000 officers to set up checkpoints and to disperse groups.
The government of New South Wales reported 210 new infections in Sydney and surrounding areas from the Delta variant outbreak.
Tokyo's metropolitan government announced a record number of 4,058 infections in the past 24 hours. Olympics organisers reported 21 new COVID-19 cases related to the Games, bringing the total to 241 since July 1.
A day earlier Japan extended its state of emergency for Tokyo to the end of August and expanded it to three prefectures near Tokyo and to the western prefecture of Osaka.
Olympics organisers said on Saturday they had revoked accreditation of a Games-related person or people for leaving the athletes' village for sightseeing, a violation of measures imposed to hold the Olympics safely amid the pandemic.
The organisers did not disclose how many people were involved, if the person or people were athletes, or when the violation took place.
Malaysia, one of the hotspots of the disease, reported 17,786 coronavirus cases on Saturday, a record high.
More than 100 people gathered in the centre of the capital Kuala Lumpur, expressing dissatisfaction with the government's handling of the pandemic and calling on Prime Minister Muhyiddin Yassin to quit.
Protesters carried black flags and held up placards that read “Kerajaan Gagal” (failed government) – a hashtag that has been popular on social media for months.
Thailand also reported a daily record high of 18,912 new coronavirus infections, bringing its total cases to 597,287. The country also reported 178 new deaths, also a daily record, taking total fatalities to 4,857.
The government said the Delta variant accounted for more than 60 per cent of the cases in the country and 80 per cent of the cases in Bangkok.
The Delta variant is not necessarily more lethal than other variants, but much more transmissible, Supakit Sirilak, the director-general of Thailand's Department of Medical Sciences, told Reuters.
China is battling an outbreak of the Delta variant in the eastern city of Nanjing which has been traced to airport workers who cleaned a plane which had arrived from Russia.
Nanjing has reported 190 locally transmitted cases of the Delta variant since July 20, while there has been a total of 262 cases across the country, figures released on Saturday showed.
Vietnam, which is grappling with its worst COVID-19 outbreak, on Saturday also announced tougher measures, saying from Monday it would impose strict curbs on movement in 19 cities and provinces throughout the southern part of the country for another two weeks.
COVID-19 infections have increased by 80 per cent over the past four weeks in most regions of the world, WHO Director-general Tedros Adhanom Ghebreyesus said on Friday.
"Hard-won gains are in jeopardy of being lost, and health systems in many countries are being overwhelmed," Tedros told a news conference.
The Delta variant, first detected in India, is as contagious as chickenpox and far more contagious than the common cold or flu, the US Centers for Disease Control said in an internal document reported this week.
It can be passed on even by vaccinated people and may cause more serious disease than earlier coronavirus strains, the CDC document said.