Germany's Robert Koch Institute (RKI) for infectious diseases on Thursday reported more than 11,200 new COVID-19 cases over the past 24 hours and the organization expressed grave concern as the virus threatened to spiral out of control.

It is the first time since the start of the pandemic that more than 10,000 new cases in Germany were recorded in a 24-hour period and the second time in a matter of days that the country has reported a new daily high. 

"The situation has become very serious overall," Dr. Lothar Wieler, head of the RKI, said.

Germany is now registering more than 50 infections per 100,000 people over a one-week period. The so-called seven-day incidence rate, which is used by authorities to decide when to tighten restrictions, is currently at 56 for the entire country, according to RKI data. 

Read more: Opinion: Germany faces a hard coronavirus pandemic winter

The spike in cases has prompted officials to introduce tougher measures on public life to stem the spread of the virus.

At a press conference on Thursday, Wieler once more stressed the importance of adhering to Germany's rules for curbing the pandemic — social distancing, hand-washing, masks and frequent airing of interior spaces. He also repeated warnings on holding private parties, saying these appeared to be one of the main sources of infections.

Wieler also called on Germany's local health authorities to maintain their efforts despite the increased burden in recent days.

New travel warnings

Meanwhile, the German government has issued travel warnings for popular ski regions in Austria, Italy and Switzerland, as well as for all of Ireland and Poland. Mainland Britain is also now viewed as a high risk area.

Under the warnings, which take effect from Saturday, travelers coming back to Germany must quarantine for 10 days.

The isolation can be lifted, however, if a negative test result is provided five days after returning.

RKI urges Germans: 'Stick to the rules' 

On Wednesday the RKI's Wieler told DW that he's confident that Germany can curb the spread of the virus — as long as people stick to the rules.

"We don't see so many outbreaks at workplaces or in public transportation, but it's mostly coming together in privacy, in parties and also in services and weddings," Wieler said. "We shouldn't have too many of these events," he added. 

Read more: Coronavirus: Germany's confusing patchwork of restrictions

Looking to the winter, the chief of Germany's disease control agency said that Germany's hospitals are "well prepared" to handle a potential spike in COVID-19 patients, adding that Germany has a high number of intensive care units relative to the population. 

"Of course, we have learned from the first time, the first peak that we had in April and March," he said.

"If we can calm down the numbers, we can manage it, and that's the most important [thing] — but we can only bring down the numbers if we stick to these rules," Wieler emphasized.

Read more: Making sense of coronavirus infection statistics

Health minister tests positive 

The record spike in cases comes shortly after German Health Minister Jens Spahn tested positive for COVID-19 on Wednesday. 

The German health ministry said that 40-year-old Spahn had immediately gone into isolation and that so far he has developed "cold-like symptoms."

The health ministry confirmed all those in contact with Spahn had been informed, though no members of Chancellor Angela Merkel's Cabinet will be self-isolating — despite having met with the health minister during a meeting earlier on Wednesday.

wmr, jsi/rs (dpa, AFP, Reuters)