COVID-19 deaths and cases are on the rise again globally in a dispiriting setback that is triggering another round of restrictions and dampening hopes for a return to normal life.

The World Health Organization reported Wednesday that deaths climbed last week after nine straight weeks of decline. It recorded more than 55,000 lives lost, a 3% increase from the week before.

Cases rose 10% last week to nearly 3 million, with the highest numbers recorded in Brazil, India, Indonesia and Britain, WHO said.

The reversal has been attributed to low vaccination rates, the relaxation of mask rules and other precautions, and the swift spread of the more-contagious delta variant, which WHO said has now been identified in 111 countries and is expected to become globally dominant in the coming months.

Sarah McCool, a professor of public health at Georgia State University, said the combination amounts to a “recipe for a potential tinderbox.”

“It’s important that we recognize that COVID has the potential for explosive outbreaks,” warned Dr. David Dowdy, an infectious disease specialist at Johns Hopkins University.

Amid the surge, the death toll in hard-hit Argentina surpassed 100,000. Daily coronavirus deaths in Russia hit record highs this week. Britain recorded a one-day total of more than 40,000 new cases for the first time in six months.

In the U.S., with one of the highest vaccination rates in the world, newly confirmed infections per day have doubled over the past two weeks to an average of about 24,000, though deaths are still on a downward trajectory at around 260 a day.