After barely weeks of relative normality, surging coronavirus cases have forced governments around the world to reimpose local lockdown restrictions and roll back the reopening of bars, restaurants and other businesses, affecting hundreds of millions of people.

In the United States, nearly two dozen states have paused or reversed their reopening plans as coronavirus cases have spiked. On Tuesday, California recorded more than 11,000 new coronavirus cases, the states highest single-day total since the start of the pandemic.

In India, the northern state of Bihar , home to 125 million people, imposed a 15-day lockdown to combat the spread of the coronavirus on Tuesday. Hours later, the southern city of Bengaluru , home to some 13 million people and a major IT hub for international corporations, began a weeklong lockdown as well.

The city, once hailed for its success at containing the coronavirus, has since become a case study for what can go wrong if authorities and residents lower their guard too quickly.

Venezuelas capital of Caracas was also ordered into a strict lockdown on Wednesday, while in Spain, some 160,000 people in the Catalonia region became the first in the country to return to confinement, as authorities scrambled to control a fresh surge of coronavirus infections just weeks after the nationwide lockdown was lifted.

Under the reimposed restrictions, residents of the city of Lleida and nearby towns are allowed to leave their homes only for essential activities. Barcelona is also considering reimposing lockdown restrictions after coronavirus cases there tripled in a week .

These measures follow similar moves in Australia, where last week authorities forced approximately 5 million people into a six-week lockdown in Melbourne amid a spike in cases there. Officials in Australias two most populous states, Victoria and New South Wales, said on Wednesday that even harsher restrictions may be imposed if the outbreak is not controlled quickly.

On Thursday, Victoria recorded 317 new coronavirus cases , a daily record, and the states health officer warned that the local outbreak may still not have reached its peak.