NEW YORK, Feb 22 (Reuters) - Muslim Americans have helped raise more than $84,000 to repair vandalized headstones at a Jewish cemetery in St. Louis, Missouri, according to an online fundraising page, amid attacks and threats against Jewish institutions.

About 170 headstones were toppled or damaged at the century-old Chesed Shel Emeth Society cemetery over the weekend, according to cemetery staff.

Some Jewish groups described the vandalism and threats as the latest evidence that anti-Semitic groups have been emboldened by the election of Donald Trump as U.S. president. His campaign last year drew the support of white nationalists and right-wing groups, despite his disavowals of them.

"Muslim Americans stand in solidarity with the Jewish-American community to condemn this horrific act of desecration," the fundraisers said on their website.

More than 3,000 people had donated $84,261 as of Wednesday afternoon. Cemetery staff declined to comment.

Jewish community centers across the United States have reported a surge in bomb threats, all of which have so far proved to be hoaxes.

On Wednesday, the Anti-Defamation League, one of the country's most prominent Jewish advocacy groups, said its national headquarters in New York City received an anonymous bomb threat but was later given the all clear.

New York Governor Andrew Cuomo ordered state police to investigate and work with federal and local law enforcement. In a statement, Cuomo said the threats were "now a national crisis" because of their regularity.

Trump condemned the previous threats as anti-Semitism for the first time on Tuesday after repeatedly declining to do so when asked by journalists last week. Some Jewish organizations have criticized his approach, saying they fear that the groups that supported Trump had become more active.

The fundraising effort was launched by Linda Sarsour, a liberal political activist, and Tarek El-Messidi, the founding director of Celebrate Mercy, a non-profit organization that teaches the public about Mohammad, the founder of Islam.

On Tuesday night, Sarsour posted on Twitter that she was raising the funds "in solidarity with our Jewish sisters and brothers." The organizers of the fundraising campaign said they would donate any excess funds to repair "any other vandalized Jewish centers."

Sarsour was a supporter of U.S. Senator Bernie Sanders in his bid to become the Democratic Party's presidential candidate, and was one of the organizers of the Women's March on Washington, which drew hundreds of thousands of protesters on Jan. 21, the day after Trump's inauguration.

(Reporting by Jonathan Allen; editing by Grant McCool) ((jonathan.allen@reuters.com; +1 646 223 5371; Reuters Messaging: jonathan.allen.thomsonreuters.com@reuters.net))