The situation is “very worrying,” said Lothar Wieler, president of the Robert Koch Institute (RKI), during a press conference in Berlin.

He urged people to adhere to the hygiene guidelines designed to prevent infections, such as social-distancing, wearing a mask and frequently washing hands.

Lothar criticized those who were not taking the pandemic seriously, taking aim at partygoers whom he called “reckless.”

Holidaymakers were also urged to stick to the rules while abroad.

Wieler said it was too early to say whether this was the beginning of a second wave of infections, but he did not rule it out.

Late last week, the number of new coronavirus cases confirmed in Germany during a 24-hour period surpassed the 800 mark, after having previously coming in at between 300 and 500.

The numbers have decreased somewhat since Friday, when 815 cases were recorded, to more than 700 on Saturday and more than 600 on Tuesday.

The majority of cases are said to be linked to local outbreaks in the states of North Rhine Westphalia and Baden-Wuerttemberg.

Germany has gradually lifted many of the restrictions it introduced in mid-March in response to the pandemic, while masks have been made mandatory in shops and on public transport.

Germany also opened its borders to a number of countries from mid-June, with people returning from high-risk regions to undergo mandatory testing under new rules.

There was some good news out of Germany in the fight against coronavirus, after the company Biontech announced together with its US partner Pfizer that it had cleared a regulatory hurdle to test a potential vaccine.

“Today, we are starting our late-stage global study, which will include up to 30,000 participants,” Biontech chief executive Ugur Sahin said in a statement released on Monday.

The phase 2/3 clinical trial will test whether the BNT162b2 vaccine does in fact prevent novel coronavirus infection.

According to the World Health Organization, four other vaccine trials are in a similarly late stage of testing.