The Philadelphia School District will keep a Germantown elementary school closed until Wednesday to fix a mold problem discovered last week, the district said Monday.

John B. Kelly Elementary School, which has about 650 students, was expected to reopen Tuesday but the district said it needed more time for the "final cleanup." Students are now scheduled to return to school on Wednesday. Staff, however, was ordered to report to Hill Freedman World Academy, 1100 Mount Pleasant St., on Tuesday.

The mold was discovered last Wednesday in several classrooms at the school, located at 5116 Pulaski Ave., due to heating, ventilation, and air-conditioning issues and condensation damage, officials said.