FALL RIVER -- Swastikas and anti-Semitic language were written on at least 30 gravestones at the Hebrew Cemetery on McMahon Street over the weekend, police said.

The police department became aware of the graffiti Sunday when a cemetery maintenance worker saw the graffiti and reported it to police, police Sgt. J.T. Hoar said Tuesday.

No arrests have been made yet and an investigation is ongoing.

Dozens of gravestones were tagged with the anti-Semitic graffiti, apparently scrawled in black marker. About 10 gravestones were defaced with swastikas. On one gravestone was written the words “heil Hitler,” and on another, “Hitler was right.”

A veteran’s gravestone was one of several defaced with an ethnic slur.

Above the menorah carved into one gravestone was the phrase, “Oy vey! This is MAGA country,” an apparent reference to President Donald Trump’s campaign slogan, “Make America Great Again.”

“If that was written on a gravestone, then that person is connecting the slogan of our current president with his own anti-Semitism,” said Rabbi Jacqueline Romm Satlow, who oversees the UMass Dartmouth Center For Jewish Culture, who upon learning of the incident said she was sad and disheartened.

Two gravestones were defaced with the words, “Day of the Rope,” an apparent reference to the novel, "The Turner Diaries," which is about a white supremacist army that overturns the United States government, according to the Anti-Defamation League.

According to the anti-hate group, the work of fiction is one of the most widely read books by members of the alt-right. The “Day of the Rope” marks the start of the white supremacist revolution and the beginning of a genocide.

The defaced tombstones were on the north side of the cemetery, which was established in the late 1800s, according to the Jewish Cemetery Association of Massachusetts’s website, which maintains a directory of Jewish cemeteries in the state.

According to the Fall River Public Library, the cemetery was formerly associated with Congregation Adas Israel, which stopped services in 2012 when the former synagogue on Robeson Street was sold to The Word of Life Community Church.

Jeffrey Weissman, who served as president of Congregation Adas Israel, could not immediately be reached.

Anti-Semitic incidents are on the rise nationwide, said Satlow. In Massachusetts, the ADL recorded 177 anti-Semitic incidents in 2017, a 42 percent increase over 2016.

Satlow said that while difficult to pinpoint one reason for the increase, it’s clear that “people who hate, for some reason, feel empowered more empowered than they did a few years ago.”

In 2016, a swastika was painted on the sign for the Kollel Center for Jewish Studies outside the orthodox synagogue at 671 East Ave., in Pawtucket, Rhode Island. Shortly thereafter, spray-painted swastikas and hateful language were discovered on a walkway at Cranston Stadium. The following year, eight swastikas were painted near a historically African-American church in New Bedford.

Police on Sunday had also received a report that a suspicious vehicle had been parked in the cemetery for two days, but the results of further investigation, announced on Tuesday, show that the vehicle was not connected to the graffiti. Two occupants in that vehicle have been ruled out as suspects.

Editor's Note: This story has been updated with new information regarding the discovery of the graffiti.