Parents of students at Bernice McDowell Elementary School received the note on Wednesday.
In the note, principal Lynne Borg told parents two additional bed bugs were found inside a student's book.
She says the source of bed bugs cannot be determined and to avoid transporting the bugs, Borg asked students to keep all text and library books inside the school.
Parents were also asked to refrain from sending students to school with backpacks. The letter says students can bring items in a clear plastic tote.
Lacey Lloyd, who has a 1st-grader at the school, says she was first made aware of the bugs on Friday.
"Last week I kept him home because I didn't know whose classroom it was and then this week I thought everything was taken care of. So, he's been going to school with his coat, his backpack, everything, books," Lloyd said.
The letter urged parents to contact a doctor or the school nurse if they notice any bed bug bites, but said it is unlikely that the school is facing an infestation.
Lloyd says She found out this week the bugs were found in her son's classroom. Her biggest concern is that she will get infested.
"I have at least three beds in my house and that's not something I want to have to deal with," she said.
The entire school will be inspected and treated after class is dismissed on Friday.
Sheryl Szafran is keeping her son home from school until the bed bugs are gone.
"I would like to see them take care of the issue and get it done properly, and not have this issue again," she said.