A hate crime task force in New York is to investigate an attack on more than a dozen headstones in a Jewish cemetery in Rochester.
It is the third known case of a Jewish cemetery being desecrated in the US in the last two weeks.
Democratic New York Governor Andrew Cuomo ordered the investigation at Waad Hakolel Cemetery.
Headstones were toppled and images of the deceased were scratched off at least half a dozen of them.
Director of Community Relations at the Jewish Federation of Greater Rochester, Karen Elam, said it was not clear how long ago the vandalism had happened.
There was no immediate comment from officials at the cemetery.
This has to stop. https://t.co/VOSZOw1M2E— Kirsten Gillibrand (@SenGillibrand) 3 mars 2017
Scores of volunteers have stepped in to help clean up and restore a Jewish cemetery in Philadelphia where vandals damaged hundreds of headstones.
Volunteers of all faiths turned up at the cemetery after news of the vandalism spread last weekend. Construction workers have offered their services for free.
The Anti-Defamation League is offering a 10,000 US dollar reward for information leading to an arrest. A police organisation is offering 3,000 dollars.
The Jewish Community Center Association of North America says centres and day schools in 11 states received bomb threats on Monday. No devices were found.
Officials say the buildings have been cleared and have resumed normal operations. The FBI is investigating. It is the fifth wave of bomb threats against Jewish community centres and institutions since January.
The US president has condemned the threats and attacks. However, he has also questioned whether some perpetrators may be opponents of his who are seeking to link his new presidency with a rise in anti-Semitism.