Germany on Tuesday toughened a partial lockdown and extended it to February 14, with Chancellor Angela Merkel warning of possible border checks to contain "the danger" of new coronavirus variants believed to be more contagious.

Speaking after hours of crisis talks with the leaders of Germany's 16 states, Merkel said the latest restrictions were necessary as "a precaution for our country, the health of our citizens and also for the economy".

According to a final text seen by AFP, Merkel and the state premiers agreed to make medical masks mandatory on public transport and in shops -- meaning only surgical masks or the so-called FFP2 masks will be allowed.

They also said employers must make it possible for staff work from home wherever it is feasible.

While vaccination is underway, Germany has maintained and extended restrictions first imposed in November
While vaccination is underway, Germany has maintained and extended restrictions first imposed in November POOL / Kay Nietfeld

The measure goes beyond previous appeals to companies to do more to keep people out of offices and off public transport.

"All our efforts to contain the virus are threatened by a serious danger," Merkel told reporters, pointing to a new strain that has sparked a surge in infections in Britain and Ireland.

"There is still time to contain the danger," she said. "We must act now."

Germany closed restaurants, leisure and sporting facilities in November, then expanded the shutdown in mid-December to include schools and most shops to halt runaway growth in new coronavirus infections.

Germany got out of the first wave of the coronavirus pandemic relatively well, but a second wave hit Europe's biggest economy hard
Germany got out of the first wave of the coronavirus pandemic relatively well, but a second wave hit Europe's biggest economy hard AFP / STEFANIE LOOS

They will all remain closed until February 14 now.

Merkel's spokesman Steffen Seibert said earlier the measures so far had brought about a "flattening of the infections curve", noting that the number of patients in intensive care had fallen slightly.

Tuesday's talks between Merkel and state premiers were brought forward by a week because of concerns over virus variants recently discovered in South Africa and Britain.

Merkel said Germany would use an EU summit on Thursday to call for "synchronised measures" to rein in the spread of the new strains.

Germany shuttered restaurants, leisure and sporting facilities in November, then expanded the shutdown in mid-December to include schools and most shops
Germany shuttered restaurants, leisure and sporting facilities in November, then expanded the shutdown in mid-December to include schools and most shops AFP / STEFANIE LOOS

She warned that Europe's top economy may have to install border checks if neighbours fail to find a deal within the bloc, noting the many cross-border commuters every day.

"If countries should decide to take different paths... then you have to be ready to say then, we'll have to reintroduce border controls. We don't want that, we want to find an agreement with our partners," she said.

Germany survived the first wave of the coronavirus pandemic relatively well, but a second wave hit Europe's biggest economy hard.

New infections have soared far above the 50 per 100,000 people threshold set by the government. And last Thursday, the country saw a new high in daily deaths with 1,244.

On Tuesday, daily deaths reached 989 though health authorities said they might have been inflated after a lag in weekend reporting. More than 11,000 new cases were recorded.

Seibert noted on Monday that the incidence rate was still at over 130 per 100,000 people, and that Germany "must more quickly" bring that down to 50.

Experts have been alarmed by data showing that Germans appeared to be moving around almost as normal this winter, unlike in the spring when a shutdown appeared to have caused a drastic drop in mobility.

The mobility of Germans was only 15 percent below that of a year ago, according to data from mobile phone signals analysed by disease control agency Robert Koch Institute and Berlin's Humboldt University.

RKI chief Lothar Wieler has meanwhile pleaded for rigorous implementation of curbs that have already been ordered, saying that there were too many exceptions allowed.

In northern Germany, officials were planning to take more drastic measures against people who breach quarantine rules.

Schleswig-Holstein state's justice ministry is turning a youth detention centre into a forced quarantine site for those who do not isolate themselves when required to.