Associated Press

LONDON — Corks popped, beats boomed out and giddy revelers rushed onto dancefloors when England’s nightclubs reopened Monday as the country lifted most remaining coronavirus restrictions after more than a year of lockdowns, mask mandates and other pandemic-related curbs on freedom.

For clubbers and nightclub owners, the moment lived up to its media-given moniker, “Freedom Day.” But the big step out of lockdown was met with nervousness by many Britons and concern from scientists, who say the U.K. is entering uncharted waters by opening up when confirmed cases are not falling but soaring.

As of Monday, face masks were no longer legally required in England, work-from-home guidance ended and, with social distancing rules shelved, no limits existed on the number of people attending theater performances or big events.

Nightclubs were allowed to open for the first time in almost 18 months, and from London to Liverpool, thousands of people danced the night away at “Freedom Day” parties starting at midnight.

“I’m absolutely ecstatic,” clubgoer Lorna Feeney said at Bar Fibre in the northern England city of Leeds. “That’s my life, my soul — I love dancing.”

At The Piano Works in London, patrons packed the area around the cordoned-off dance floor on Sunday as a host led a countdown to midnight.

Once a ceremonial ribbon was cut, the crowd ran toward the dance floor as confetti canons went off and a disco ball spun above. Soon, unmasked clubgoers dancing to a live band’s rendition of Whitney Houston’s “I Wanna Dance With Somebody” filled the floor.

But while entertainment businesses and ravers are jubilant, many others are deeply worried about scrapping restrictions at a time when COVID-19 cases are on a rapid upswing because of the highly infectious delta variant first identified in India. Cases topped 50,000 per day last week for the first time since January. Deaths remain far lower than in the winter thanks to vaccines, but have risen from less than 10 a day in June to about 40 a day in the past week.

Prime Minister Boris Johnson, who has dialed down talk of freedom in recent weeks, urged the public to “proceed cautiously” and “recognize that this pandemic is far from over.”

Or, as Deputy Chief Medical Officer Jonathan Van-Tam put it at a televised news conference: “Don’t tear the pants out of this.”

In a reminder of how volatile the situation is, the prime minister was spending “Freedom Day” in quarantine. Johnson and Treasury chief Rishi Sunak are both self-isolating for 10 days after contact with Health Secretary Sajid Javid, who has tested positive for COVID-19.

Johnson initially said he would take daily tests instead of self-isolating — an option not offered to most people — but U-turned amid public outrage.

The prime minister is among hundreds of thousands of Britons who have been told to quarantine because they have been near someone who tested positive. The situation is causing staff shortages for businesses including restaurants, car manufacturers and public transport.

Globally, the World Health Organization says cases and deaths are climbing after a period of decline, spurred by the delta variant. Like the U.K., Israel and the Netherlands both opened up widely after vaccinating most of their people, but had to reimpose some restrictions after new infection surges. The Dutch prime minister admitted that lifting restrictions too early “was a mistake.”

In the U.S., many areas abandoned face coverings when the Centers for Disease Control and Prevention said fully vaccinated people didn’t need to wear them in most settings. Some states and cities are now trying to decide what to do as cases rise again.