Paris closed all bars amid a sharp uptick in the number of coronavirus cases among young adults, as the United Kingdom admits nearly 16,000 positive cases previously went unreported due to an IT error.

Bars in and around the French capital were ordered shut Monday amid a sudden rise in positive COVID-19 cases among those aged 20-30. Local authorities said restaurants could remain open, as long as they enforce added restrictions, including taking the names and phone numbers of all diners, limiting parties to just six people, and providing hand sanitizer at every table, The Guardian reported.

WORLD LEADERS REACT AFTER TRUMP, FIRST LADY TEST POSITIVE FOR CORONAVIRUS 

“This morning we enter a new phase. We are adapting all the time to the development of the virus. These measures are aimed at slowing the spread of the virus because it is spreading too quickly,” Paris police prefect, Didier Lallement, said at a press conference Monday, adding that dining establishments allowed to remain open are those “whose main activity is serving food.”

The new measures came just hours after Aurelien Rousseau, director-general for the Ile-de-France Regional Health Agency based in Paris, declared a “maximum alert” in the area in effect for the next 15 days beginning Tuesday. The sale and consumption of alcohol will be banned after 10 p.m., among other restrictions.

In this Sept. 26, 2020 file photo, people enjoy a drink in a cafe terrace in Paris. French authorities have placed the Paris region on maximum virus alert on Monday, banning festive gatherings and requiring all bars to close but allowing restaurants to remain open, as numbers of infections are rapidly increasing. (AP Photo/Lewis Joly, File)

In this Sept. 26, 2020 file photo, people enjoy a drink in a cafe terrace in Paris. French authorities have placed the Paris region on maximum virus alert on Monday, banning festive gatherings and requiring all bars to close but allowing restaurants to remain open, as numbers of infections are rapidly increasing. (AP Photo/Lewis Joly, File)

BORIS JOHNSON WISHES TRUMP 'SPEEDY RECOVERY' FROM COVID-19 

Rousseau said the number of coronavirus cases in the region surrounding Paris had risen to 270 per 100,000 population, and, perhaps more alarmingly, to more than 500 per 100,000 population among those aged 20-30. He added that 35% of intensive care hospital beds in the region were occupied by COVID-19 patients, and the number was projected to rise to 50%

Meanwhile, in the United Kingdom, Public Health England said 15,841 positive cases between Sept. 25 and Oct. 2 were left out of the daily coronavirus figures for the country.

Those who tested positive were notified but those who might have come in contact with them were not, meaning the technical error hampered tracing efforts. With the unreported cases now accounted for, the UK showed 12,872 new cases Saturday and 22,961 new cases Sunday, according to the BBC.

CLICK HERE TO GET THE FOX NEWS APP

This comes as the government of Ireland recommended Sunday a return to a nationwide lockdown for the next four weeks, as the country braces for a second wave of infections in Europe.