BERLIN— New COVID-19 infections in Germany have reached their highest level in nearly three months amid a steady rise powered by the delta variant.

The national disease control center, the Robert Koch Institute, said Saturday that 51.6 new cases per 100,000 residents were reported over the last seven days. It’s the first time since May 25 that the infection rate has been above 50, but it has been increasing since hitting a low of 4.9 in early July.

The disease control center said that 8,092 new cases were reported over the past 24 hours — up from 5,644 a week earlier. More cases are getting detected as summer vacations end and children return to schools in some parts of Germany.

German authorities have been trying to reinvigorate the country's COVID-19 vaccination drive, which has slowed considerably. Official figures showed that 63.8% of Germany’s population had received at least one vaccine dose as of Thursday and 58.5% was fully vaccinated.