Moscow on Sunday recorded its worst daily coronavirus death toll and South Africa reimposed restrictions for two weeks to combat a surge in the highly contagious coronavirus Delta variant.
Indonesia saw more than 21,000 infections in a day, a record, as countries across the Asia-Pacific region extended or reimposed restrictions to tackle fresh waves of cases.
Even as vaccination drives have brought down infection numbers in many wealthy countries, the Delta strain of the virus remains a concern.
The variant is now in 85 countries and is the most contagious of any Covid-19 strain so far identified, according to the World Health Organization.
While in much of Europe and the United States curbs on daily life are easing as vaccination programmes bear fruit, Russia is grappling with a deadly third wave.
Moscow on Sunday recorded 114 Covid-19 deaths in the last 24 hours, a day after Saint Petersburg set Russia's previous highest figure.
Saint Petersburg has hosted six Euro 2020 matches and is due to host a quarter-final on Friday, with spectator numbers capped at half but still upwards of 26,000 people.
Russia has seen an explosion of new infections since mid-June driven by the Delta variant. Officials in Moscow are pushing vaccine-sceptic Russians to get inoculated.
Rapid, large-scale vaccination was the only answer, Moscow Mayor Sergei Sobyanin told state-run television on Saturday.
"Nobody has invented any other solution."
- S.African 3rd wave –
South Africa's President Cyril Ramaphosa announced fresh restrictions in a televised address Sunday. The country, he said, "is facing a massive resurgence of infection".
The government has banned the sale of alcohol, and all gatherings except for funerals, capped at 50 people. The overnight curfew has been extended by an hour, and restaurants and other outlets can now only serve take away food.
"The peak of this third wave looks set to be higher than the previous two," the president warned. South Africa, the worst-hit nation on the continent, has already suffered nearly 60,000 deaths.
The Delta variant is also feeding fresh outbreaks in Southeast Asia and Australia where authorities have brought back or extended restrictions.
More than five million Sydney residents endured their first full day of a two-week lockdown Sunday. Restaurants, bars and cafes were shuttered and stay-at-home orders were issued, leaving the city centre virtually deserted.
More than 110 Covid-19 cases have been reported in Sydney since a driver for an international flight crew tested positive in mid-June for the Delta variant.
The flare-up has been a shock for a place that had returned to relative normality after months with few local cases.
Australia's northern city of Darwin also entered a separate snap 48-hour lockdown on Sunday after a handful of cases linked to a coronavirus outbreak on a remote gold mine.
- Restrictions reimposed –
Similar spikes in infections have been seen across Southeast Asia, with Indonesia setting a new daily infection record of more than 21,000.
Hospitals are flooded with patients in the capital Jakarta and other Covid-19 hotspots across the region's hardest-hit nation.
Thailand will from Monday reimpose restrictions on restaurants, construction sites and gatherings in the capital Bangkok. Its latest wave began in April when a cluster was found in upscale Bangkok clubs.
Premier Prayut Chan-O-Cha has said he plans to fully reopen the country by October, but this would require hitting a target of vaccinating 50 million Thais in four months.
In neighbouring Malaysia, the prime minister announced a nationwide lockdown already in place for about a month will continue. He gave no date for the lifting of restrictions.
Bangladesh also said it would impose a new national lockdown from Monday, with offices shut for a week and only medical-related transport allowed.
The announcement prompted tens of thousands of migrant workers to desert the capital Dhaka, where the lockdown will cut off their revenue sources.
"During lockdown, there is no work," Fatema Begum, 60, told AFP while waiting for a ferry. "And if we don't work, how do we pay rent? So we packed up everything and are going back to our village."
Infections declined in May but started to rise again this month, with a pandemic high of 119 deaths on Sunday, according to the health ministry.
Luxembourg Prime Minister Xavier Bettel's office announced he is self-isolating for 10 days after testing positive for Covid shortly after a European Union summit.
None of the other 26 EU leaders who attended is considered a contact case, a statement said.
AstraZeneca and the University of Oxford on Sunday began trials to test a modified vaccine against the Beta variant, which first emerged in South Africa.