Police were called to an Ottawa Valley high school on Tuesday due to what the school board is calling a “potential safety concern.”

OPP officers were at Renfrew Collegiate Institute, a Renfrew County District School board spokesperson said Tuesday. The school remained open for the day and classes went ahead as usual.

"As this is an ongoing investigation, the OPP has asked us not to divulge any more information at this time," the spokesperson said in a statement. "The OPP are on site all day today at the school, and the school remains open to students and staff."

"We look forward to providing an update to our parents/guardians and our school communities by the end of the day today once we have received further guidance from the OPP on this matter."

A photo obtained by CTV News Ottawa showed that someone scrawled the words 'Shoot up June 7th' on a wall at the school.

The board posted a note on Facebook on Monday saying police would be at the school Tuesday.

"Earlier today it came to our attention that there was concerning graffiti suggesting a potential safety concern found in our building,” the post said. "We know that this information has made it into the community and is very upsetting for our students and families.

"Please be assured that we have taken this potential safety issue very seriously and are fully investigating with the support of the OPP."

The board promised to keep parents and guardians updated as more information became available.

Nicole Malcolm has two daughters who attend Renfrew Collegiate, and says that while the school would not elaborate on the safety concern, others did.

“Mainly that there were things written in bathroom stalls both women and men,” says Malcom, adding that she spoke to officers with the OPP, who assured her that the school was safe; however, few students attended class on Tuesday. “My one daughter, in Grade 7, three classmates and the other one about the same … There’s too much commotion going on here today so I figured I might as well bring them home and let them do their work on google classroom.

“It’s very sad,” says Malcolm. “We’re seeing more and more of it but the police response is amazing and they’re keeping us safe.”