ANDOVER (CBS) – Police and school officials are investigating after three swastikas were found scrawled on a classroom desk inside a Jewish teacher’s classroom just hours before Hanukkah was set to begin.

It is the third time in recent months that a swastika was discovered at Andover High School.

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The town manager, police department, and school system sent out a joint statement condemning the actions, which are being investigated as a hate crime.

“We must respond to the situation that presents itself to us, and we cannot ignore hatred and intolerance because they are uncomfortable topics of conversation. We must educate ourselves and our children,” Superintendent Sheldon Berman said in a statement. “We seek to find those responsible for these acts, but we also know that we must educate our entire community if we hope to prevent these acts from reoccurring.”

School officials said they will be reaching out to local religious and civic leaders to hold a public forum at Andover High School early in the new year.

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“This is a very hurtful thing to the teachers and I know that they expressed significant concern about it,” said Berman. “They felt that this was a sign of disrespect for them.”

The Anti-Defamation League of New England called Andover’s response to the incident “swift and thorough.”

“They’re making a conscious effort to not keep it a secret, to not just clean the desk and pretend it never happened,” said Robert Trestan, ADL New England Regional Director said. “They’re using it as an opportunity … to educate these students and start these discussions.”

The ADL of New England says there have been 13 swastika incidents reported to the organization since November 1. The incidents took place in 11 different communities.

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One community – Reading – had multiple incidents.