BERLIN — Germany is closing most stores and schools, and further limiting social contacts in an effort to drive down the rate of coronavirus infections that have remained stubbornly high in recent weeks.

Chancellor Angela Merkel said she and the governors of Germany’s 16 states agreed Sunday to step up the country’s lockdown measures from Dec. 16 to Jan. 10 to stop the exponential rise of COVID-19 cases.

“We are forced to act, and we’re acting, too,” Merkel told reporters in Berlin.

Existing restrictions imposed in November failed to significantly reduce the number of new infections, she said. Germany recorded 20,200 newly confirmed cases and 321 additional deaths Sunday, a high number for the weekend when many local authorities don’t report figures.

With the exception of Christmas, the number of people allowed to meet indoors will remain restricted to five, not including children under 14.

The sale of fireworks traditionally used to celebrate New Year’s will be banned, as will the outdoor sale of alcohol.