Europe, the worst-hit continent, passed the threshold of one million coronavirus deaths, while South Asian countries battle a spiralling outbreak of the disease that has crippled the global economy.
Vaccination drives are giving hope to people fed up with restrictions that are well into a second year, and India -- which is experiencing a record surge in cases -- was given a boost as it authorised Russia's Sputnik V Covid-19 drug.
The total number of virus deaths is approaching three million, according to an AFP tally of official data, as the World Health Organization warned infections are rising exponentially despite efforts aimed at stopping them.
From Indonesia to Egypt, many Muslims around the world started Ramadan after religious leaders confirmed the month of fasting would begin on Tuesday, many facing virus restrictions.
- 'I am so happy' -
Jakarta's newly renovated Istiqlal Mosque -- South-East Asia's largest -- welcomed worshippers for the first time on Monday night after more than a year of closure because of the pandemic.
Mohamad Fathi, a resident of the Indonesian capital, told AFP this year's Ramadan was happier than in 2020, when people were banned from taking part in tarawih (evening) prayers.
"Last year it was gloomy as we were not allowed to go to the mosque for tarawih prayers," he said.
"But this year, I am so happy finally we can go to the mosque to perform tarawih prayers at the mosque although we are under strict health protocol during the prayer."
The government of the world's most populous Muslim-majority nation has imposed limits, with mosques only able to host people at a maximum of 50 percent capacity. Worshippers are required to wear masks and bring their own prayer mats.
Saudi Arabia, home to Islam's holiest shrines, announced that the holy fasting month was to start on Tuesday, though authorities said only people inoculated against Covid-19 will be allowed to perform the year-round umrah pilgrimage from the start of Ramadan.
In Egypt, restrictions were much less stringent than last year as people took to the streets to mark the start of the fasting month.
- India gets Sputnik -
Pakistanis will only begin fasting Wednesday after rival moon-sighting committees agreed to a nationally applied start of what is called "Ramazan" in the country.
With the country in the grip of a third wave of the coronavirus -- the deadliest so far -- the government urged mosques to only allow prayers in open courtyards and to strictly enforce social distancing to avoid the same spike in cases which followed last year's Ramadan.
But shoppers thronged markets Tuesday ahead of fasting, sparking anxiety among some.
"We have been pleading with people to wear masks and keep their distance but it seems too much for them... people are still not ready to accept that there is a virus and we are going through a pandemic," said Zubair Mehmood, a shopkeeper in the garrison town of Rawalpindi.
In neighbouring India -- home to 1.3 billion people -- health officials have been battling a huge surge in cases in recent weeks that has prompted night curfews and a clampdown on movement and activities.
The country on Monday reported more than 161,000 new cases -- the seventh-consecutive day that more than 100,000 infections have been recorded.
Experts have warned that huge, mostly maskless crowds at political rallies and religious festivals have fuelled India's caseload, and in the Himalayan city Haridwar, maskless Hindu pilgrims have ignored social distancing pleas.
Adding Sputnik to its roster of jabs bolsters the government's ambitious goal of vaccinating 300 million people by the end of July.
In Europe -- where more than one million people have now died from the virus -- the government in hard-hit Germany agreed to controversial changes to a national infections control law, handing Berlin more power to impose tougher measures.
Those measures include a 9pm to 5am curfew and stricter rules around private gatherings and sports.
Maria Van Kerkhove, the WHO's technical lead on Covid-19, said the world was now at a "critical point" of the pandemic.
"The trajectory of this pandemic is growing... exponentially.
"This is not the situation we want to be in 16 months into a pandemic, when we have proven control measures."
The organisation also called for a halt to the sale of live wild mammals in food markets to prevent the emergence of new diseases such as Covid-19.
"Covid-19 has brought new attention to this threat, given the magnitude of its consequences," WHO spokeswoman Fadela Chaib told reporters.
Some of the earliest known cases of Covid-19 had links to a wholesale traditional food market in the Chinese city of Wuhan.