PORTLAND, Maine (AP) – Maine officials are recommending caution at more schools in the state because of the rise in coronavirus cases.

The state uses a color-coded system to categorize the level of precaution schools should use. The administration of Gov. Janet Mills, a Democrat, says Friday it’s adding schools in Knox County and Franklin County to the “yellow” category, which is an intermediate level.

Those counties join Somerset and Washington counties in the yellow category. All the other counties in the state are in the “green” category, which is the lowest level, though officials say they’re closely monitoring schools in Waldo and Kennebec counties.

The change in category for some schools came as cases surged around the state.