A Fire Department Hazmat Unit has not been able to identify the source of fumes that prompted officials to evacuate the James Sullivan Elementary School in Wissinoming this morning and declared the building safe after testing found nothing toxic in the air, the commander at the scene reported.

No students or teachers required medical treatment because of the fumes, said Fire Department Executive Chief Richard Davison.

The school at 5300 Ditmas Street was turned back to School District control for ventilation, the scene commander reported at 11:15 a.m.

The K-5 school's 500 students and staff members were relocated by bus to the Warren G. Harding School a few blocks away.

The Hazmat Unit was called in after Fire Department and Philadelphia Gas Work officials who initially responded to the school about 8:45 a.m. reported they could not determine the source of the fumes.