"We certainly take it seriously," said Penticton RCMP Sgt. Rick Dellebur.
"For that reason we have about eight members working solely on this file right now, in addition to the people that are actually stationed outside the schools."
The school district has been locking exterior doors and keeping students inside four schools in Penticton and Okanagan Falls since Wednesday.
The schools affected are:- Skaha Lake Middle School.
- Princess Margaret Secondary School.
- Penticton Secondary School.
- Okanagan Falls Elementary School.
Police are asking the public for any information to help determine the source of the letter.
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