(AP) Students begin returning to school in Maine’s largest school district on Tuesday.

Portland Public Schools send most students back to the classroom that day, though kindergarten and pre-kindergarten students don’t return until Thursday. The Portland Board of Public Education approved safety protocols for the year on Aug. 17.

The protocols include pooled testing for grades kindergarten through sixth, universal indoor masking and continued reminders about daily screening for symptoms.

The district said it’s planning to hold a virtual public forum about the pooled testing plan on Sept 1.