BERLIN — Several German states have introduced a requirement for people arriving from Sweden to self-quarantine for 14 days because of rising coronavirus infections in the Scandinavian country.

Germany had a quarantine requirement for most people arriving from abroad for over a month until mid-May, when state governments started exempting people coming from European countries.

But several states are now reintroducing the requirement for arrivals from Sweden, on the grounds that new infections there have exceeded 50 per 100,000 residents over seven days. Inside Germany, that level of infections in a region is supposed to trigger action by local authorities.

Bavaria on Tuesday followed three northern states — Schleswig-Holstein, Mecklenburg-Western Pomerania and Lower Saxony — in imposing the quarantine.

Sweden has pursued a controversial strategy which avoided a lockdown but resulted in a high per capita COVID-19 death rate. Reported infection rates in Sweden have risen slightly recently because testing rules have changed slightly, allowing new groups of people to be tested.