NEW YORK (REUTERS) - Muslim Americans have helped raise more than US$84,000 (S$118,000) to repair vandalised headstones at a Jewish cemetery in St Louis, Missouri, according to an online fund-raising 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 US 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 fund-raisers said on their website.

More than 3,000 people had donated US$84,261 as of Wednesday afternoon. (5am on Thursday, Singapore time).

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

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

The fund-raising effort was launched by Linda Sarsour, a liberal political activist, and Tarek El-Messidi, the founding director of Celebrate Mercy, a non-profit organisation that teaches the public about Muhammad, 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." Sarsour was a supporter of US Senator Bernie Sanders in his bid to become the Democratic Party's presidential candidate, and went on to become one of the organisers of the Women's March on Washington, which drew record crowds to the capital on Jan 21, the day after Trump's inauguration.

Cemetery staff, who did not respond to a request for comment, were still calculating the cost of repairing the damaged tombstones as of Tuesday.

The organisers of the fund-raising campaign said they would donate any excess funds to repair "any other vandalised Jewish centres."