Dozens of headstones were found toppled at a Jewish cemetery in Philadelphia on Sunday.

Police said that the incident at the city’s Mount Carmel Cemetery was an act of vandalism and have opened an investigation, according to a local ABC affiliate.

Police did not say whether they were treating the case as a possible hate crime.

Israel’s Foreign Ministry Spokesman Emmanuel Nahshon condemned the incident, writing on Twitter that the “Philadelphia Jewish cemetery desecration is shocking and a source of worry. Full confidence US authorities catch and punish culprits.”

New Jersey resident Aaron Mallin, who made the discovery when visiting his father’s grave, told the local TV station he hoped it was not an anti-Semitic attack.

“I’m hoping it was maybe just some drunk kids. But the fact that there’s so many it leads one to think it could have been targeted,” Mallin said.

The discovery of the vandalized Jewish headstones in Philadelphia Sunday follows a similar incident last week in which over 150 graves were damaged at a Jewish cemetery near St. Louis.

The vandalism at the Jewish graveyard in Missouri was decried by leading American Jewish groups, who called on the US authorities to take action in response to a perceived recent increase in anti-Semitic incidents in the US. It was also followed by US President Donald Trump’s first explicit condemnation over the trend.

On Wednesday, US Vice President Mike Pence visited the Chesed Shel Emeth Society cemetery outside of St. Louis where the incident took place, joining Missouri’s Jewish Governor Eric Greitens and other volunteers in an interfaith service and cleanup effort.

US Vice President Mike Pence visits a Jewish cemetery in St. Louis following an act of vandalism at the site. (YouTube screenshot)

US Vice President Mike Pence visits a Jewish cemetery in St. Louis following an act of vandalism at the site. (YouTube screenshot)

In addition to the vandalism at the Jewish cemeteries, there were also instances of anti-Semitic vandalism at Drake University in Des Moines, Iowa, and in a suburb of Buffalo, New York, over the past week.

At Drake University, an anti-Semitic slur was discovered carved into a chair in a university lecture hall. The university is investigating the incident as a hate crime.

“Let me be clear that we will not tolerate acts of oppression and hate, and will do everything in our power to deal with this,” University Provost Dr. Sue Mattison said in an email sent to students.

In the suburb of Orchard Park outside of Buffalo, about one dozen swastikas and racial slurs were drawn on cars and a building.

A nearby elementary school playground and railway overpasses were similarly vandalized.

The spray-painted swastikas and slurs were discovered on Saturday morning and were believed to have been painted late on Friday night, according to reports.

At least 11 cars and an apartment building in the Village of Orchard Park near Buffalo were vandalized with the spray-painted swastikas and slurs, according to local reports. The reports began coming in to police at 3 a.m. on Saturday and continued throughout the morning.

Public and private surveillance camera footage is being checked to find the perpetrators, according to village police. Investigators believe more than one person could be involved, according to the reports.

JTA, Raphael Ahren contributed to this report.