Hundreds of headstones, some of them more than 100 years old, were cut in half, local media reported Sunday.
A local rabbi, who was unnamed, told ABC television affiliate WPVI, that the affected graves at the historic Mt Carmel Jewish cemetery in Philadelphia's northeastern Wissinoming neighborhood also included those of one-time members of the Quaker and Muslim communities.
New Jersey resident Aaron Mallin discovered the vandalism on Sunday when he came to visit his father's grave at the cemetery.
"It's just very disheartening that such a thing would take place," he told WPVI.
Police say they are investigating the vandalism.
The Anti-Defamation League has offered a $10,000 reward for information leading to the arrest and conviction of those responsible.
Israeli Foreign Ministry spokesman Emmanuel Nahshon posted a statement on Twitter saying, "#Philadelphia Jewish cemetery desecration is shocking and a source of worry. Full confidence #US authorities catch and punish culprits."
The attack comes a week after more than 100 headstones were damaged at a Jewish cemetery in St Louis, Missouri. The incident prompted a Muslim-led crowdfunding campaign to raise more than $100,000 to repair the cemetery, and a visit by Vice President Mike Pence.
READ THESE STORIES TOO
At least 11 US Jewish centers get bomb threats
Among more recent attacks, vandals spray-painted swastikas on several cars, highway overpasses, buildings and an elementary school playground over the weekend in Buffalo, New York, The Buffalo News reported.
After remaining silent on the subject for several days, President Donald Trump on Tuesday decried the anti-Semitic threats against Jewish community centers across America as "horrible" and "painful."
However, concern is rising about his embrace by white supremacist groups and an "alt-right" movement given a platform on Breitbart, the online news outlet once headed by Trump's chief White House strategist Steve Bannon.
The White House raised eyebrows on International Holocaust Remembrance Day late last month by issuing a statement that made no mention of the six million Jews killed in the Nazi genocide.
Other groups have also been targeted. On Wednesday, a drunk white man fatally shot an Indian engineer and wounded another in Kansas City, screaming racial slurs and telling them "Get out of my country!"
