The veteran leader warned against “discussion orgies” about opening up society, in a telephone conference with leaders of her centre-right CDU party on Monday morning, participants in the call said.
Merkel urged Germans to stay disciplined in fighting the coronavirus pandemic as the country began easing some curbs, warning that there was a long way to go before claiming victory.
“We stand at the beginning of the pandemic and are still a long way from being out of the woods,” she told journalists, saying that it would be a “crying shame if we were to stumble into a relapse with our eyes wide open”.
She also also urged the public to maintain social distancing measures, such as keeping 1.5 metres apart and avoiding gatherings of more than two people, voicing her “scepticism” and “huge concern” over the population's discipline.
After an apparent race among regional leaders last month to appear the toughest in announcing lockdown measures, some politicians have begun pushing for even faster loosening than the reopening of smaller shops and schools.
Business lobbies have been pressuring the government to move faster, but initial steps agreed between Berlin and state capitals are tentative.
From Monday, shops up to 800 square metres can reopen across Germany as long as they impose hygiene controls, while next week will see selected cohorts of pupils return to classrooms.
Germany has been largely spared the worst of the coronavirus pandemic that has devastated some of its European neighbours, with deaths well below hard-hit Italy, Spain and France.
It currently has over 145,000 confirmed coronavirus cases and 4,624 deaths, among the lowest fatality rate in Europe due in part to widespread testing and intensive care capacity. Of the cases, 91,500 people are reported to have recovered.
Widespread lockdown measures were rolled out last month in line with many of its neighbours, restricting non-essential outings and closing most shops except for supermarkets and pharmacies.
As its closely watched person-to-person infection rate fell below one last week — meaning each infected person was contaminating less than one person, down from five previously — Merkel and state leaders decided to ease the lockdown.
Some leading politicians have also been critical of the measures, which vary widely across Germany's 16 states.
Some states, such as the northeastern Mecklenburg-Western Pomerania, have seen zoos and fitness studios reopen whereas others, such as Berlin's neighbouring Brandenburg allow for some registered gatherings of up to 20 people.
A sign stating that “Everything will be good” hangs in the window of an ice cream shop in Mainz, Rhineland-Palatinate that opened at noon on Monday. Photo: DPA
In eastern Saxony state, pupils taking final examinations began streaming back to classrooms, two weeks ahead of their peers in other states, where school gates will reopen only from May 4th.
Masks have however been required on public transport and in shops in the eastern state.
In the Saxon city of Leipzig, people waiting to get on trams and buses had their faces covered.
Though not yet obligatory, the German government “strongly advises” wearing a mask in public.
Bavaria on Monday said that it was joining Saxony in requiring face coverings.
Manuela Fischer, opening up her clothing store in Leipzig, said she was “incredibly happy” to be welcoming shoppers again.
In some states such as the capital Berlin, meanwhile, it would take a few more days before shops reopen.
Hesse's state premier Volker Bouffier (CDU) as well as parliamentary member Julia Klöckner (CDU) spoke out on Monday against the loosing of restrictions in Social Democratic-led Rhineland-Palatinate.
They include opening shopping malls and zoos, as well as allowing some party events to take place again.
Some of Merkel's conservative party colleagues echoed her caution.
“We will not be able to go back to our normal lives for a long time,” said Armin Laschet, the state premier of North-Rhine Westphalia, the country's most populous region.
On Friday, health minister Jens Spahn said the pandemic was “once again under control” in Germany, as the number of people infected by each person with the virus dropped below one.
But Merkel warned Monday that unless people continue to follow rules and advice like keeping their distance from others and wearing masks, the picture could again worsen.
She and her ministers will track the impact of the opening up measures over the coming days until April 30th, when the lockdown is currently set to expire.
But it could be May 8th or 9th before the true impact from reopening businesses and schools is seen, Merkel said, according to the sources.
So far most Germans have expressed overwhelming support for the `lockdown, with around 90 percent backing it according to polls earlier this month.