A man exposed himself near children playing outside King Middle School in Portland on Friday, a school official said.

In a letter addressed to families, Principal Amy Marx said the incident took place around 1:05 p.m. Friday at the Deering Oaks park playground while some students were on recess.

“While the students were playing, a few students reported to a King teacher that a male person by the swings in close proximity to them had exposed his private areas,” Marx wrote.

Staff followed school safety protocols, Marx said, by immediately moving students indoors and contacting the Portland Police Department.

Portland police are investigating the matter, a spokesperson for the department said, but they had not identified a suspect as of Friday evening.

“Our social workers and counselors are meeting with any student who may have witnessed this incident or who are affected by hearing about it,” Marx wrote.

The school will also address this issue with students across the school Monday and “use it as an opportunity to again review safety measures.”