SAN FRANCISCO (CBS SF) — Police were investigating a vandalism incident involving an Islamic symbol at the French American International school in San Francisco Tuesday.

Police believe the incident happened overnight at the independent Pre-K through 12th grade school in Hayes Valley. Twenty-three percent of the students are French nationals.

The graffiti, which includes a crescent moon and star, associated with 20th century Islam, was discovered spray-painted on a wall and playground surface. It appears to be the emblem of the Five Percent Nation, an offshoot of the U.S.-based Nation of Islam religious movement.

Among the tenets of the Five Percent Nation is that black people are the original human beings on Earth and the fathers and mothers of civilization. The group’s teachings have been referenced by rap artists and in hip-hop culture.

The SFPD Special Investigation Division is actively investigating this incident to determine if it amounts to a hate crime. Anyone with information on this crime was asked to call the Anonymous Tip Line at (415) 575-4444 or Text A Tip to TIP411 and begin the message with SFPD.