LOS ANGELES (AP) — State health officials say coronavirus cases in California remain low but have ticked up since the state reopened two weeks ago.

The small increase in cases was expected by many health experts after the nation’s most populous state broadly reopened its economy and lifted most mask restrictions for vaccinated people.

Public health officials raised concern this week with the more contagious delta variant on the rise, especially for the unvaccinated. They comprise the vast majority of new infections.

After detecting a rise in the variant, Los Angeles County recommended that vaccinated residents resume wearing face coverings indoors.