A worker hired by the school prepares to scrub the message off the building. (CBC)Charlottetown police are looking for one person in connection with threatening graffiti spray painted on a high school overnight Wednesday.

Police are reviewing surveillance tape from Colonel Gray High School, which they say shows a person painting the messages shortly after midnight.

"Right now the investigators are going over that video surveillance tape and trying to identify a person in the videotape that is responsible for the message," said deputy Chief Gary McGuigan.

The Eastern School District had workers at the school Thursday morning removing the graffiti.

"A kid will die if there is school today," said one message. "Which kid will die?" said another. Other notes containing profanities were directed at police.

Ricky Hood, the superintendent of education for the Eastern School District, said the board is confident students are safe at the school.

"We had no information coming from either the police in the community or from the school that the threat was serious," he told CBC News. "There was no one on our radar screen to lead us to believe that this was actually a serious threat."

But some students at the school said they thought classes should have been cancelled.

"I think there shouldn't be school because that's a threat that should be taken seriously," said Danielle Pickles. "Even though it's a joke, it should be taken seriously."

Jasmyn Peake, another Colonel Gray High School student, said she would likely go home early.

"You never know what could happen," she said.

Police officers were on the scene Thursday morning and a school board official said there would be a police presence throughout the day.

Hood said students were free to go home if they don't feel safe, or if their parents don't feel they are safe.

"If any student needs any support from a school counsellor or district counsellor we'd certainly make that available," he said.