TOKYO: Japan banned fans from the Olympic Games on Thursday as the Delta variant drove Covid-19 outbreaks, with the worst of the pandemic just starting to hit parts of Asia-Pacific and cases rising again in Europe and the United States. Delta is the most infectious strain of the virus since the start of the global pandemic in early 2020.

Originally detected in India months ago, it has quickly spread and today is accelerating outbreaks even in countries with high vaccination rates, leading the World Health Organization to warn that the world was at a "perilous point" as the official global death toll hit four million.

Japan, where the strain currently accounts for around 30 percent of cases, on Thursday banned spectators from Olympic venues in Tokyo - where most competitions will take place.

Earlier, Prime Minister Yoshihide Suga announced that the capital will be under a state of emergency throughout the Games, until August 22, though it will be far looser than the lockdowns seen in other parts of the world such as Australia.

The government there said Thursday it will rush 300,000 vaccine doses to Sydney as Australia's largest city - in its third week of lockdown - struggled to bring a Delta outbreak under control.

South Korea, once considered a coronavirus response model along with Australia, reported nearly 1,300 new infections on Thursday, the highest since the pandemic began. Elsewhere in Asia, Vietnam's Ho Chi Minh City has gone into lockdown. The virus threat also forced organisers Thursday to postpone the Southeast Asian Games that were due to be held in Vietnam.

Indonesia has become a global Covid-19 hotspot with death rates rising tenfold in a month to more than 1,000 on Wednesday. Hospitals in the vast archipelago of 270 million have been pushed to the brink by the flood of coronavirus cases.

The out-of-control virus surge has led to a run on ivermectin, an anti-parasite drug backed by leading politicians and social media influences as a "miracle cure" despite little evidence and health warnings. Across the globe in Brazil, which has the world's second-highest known Covid-19 death toll after the US, authorities said Wednesday that the variant has started spreading rapidly in the country's most populous state Sao Paulo.

The WHO announced Wednesday that more than four million people have died from Covid-19, but cautioned that the figure was an underestimate of the true toll. While many wealthy nations, spurred by rapid vaccination programmes, have started easing and even entirely eliminating restrictions, the WHO urged "extreme caution".

"The world is at a perilous point in this pandemic," said the UN body's chief Tedros Adhanom Ghebreyesus, accusing rich countries of hoarding vaccines and of acting "as though the pandemic is already over".

Delta is making itself felt even in the United States and Europe, where vaccination drives have been robust. France on Thursday advised its citizens against travelling to Spain and Portugal because of a Delta-caused spike in cases.

In Russia, where Delta has driven the death rate to pandemic highs recently among a vaccine-hesitant population, Moscow police have launched dozens of criminal probes to crack down on fake inoculation certificates. And Delta-fuelled cases were also on the rise in the US, where a once-rapid immunisation campaign has dropped off steeply since April. The seven-day average of new cases rose 21 percent compared with two weeks ago, Centers for Disease Control data showed Wednesday.