A school superintendent in Massachusetts has asked police to investigate after swastikas and other offensive graffiti were found on a rock outside of a school.

Harvard Public Schools Superintendent Linda Dwight sent an email to parents Friday saying that a rock in front of the Bromfield School had been vandalized with swastikas, homophobic symbols and racist words. One of the swastikas was placed over a Jewish Star of David.

Dwight says the school district condemns the graffiti. Police in the town of Harvard could not immediately be reached for comment.

The Bromfield School, located 30 miles west of Boston, has about 700 students in grades six through 12.

Last week, officials in nearby Billerica, Massachusetts, said a shuttered elementary school had been vandalized with a swastika.

(AP)