A group of Democratic U.S. senators this week urged federal law enforcement agencies to alert local police to rising threats against election officials, according to a memo seen by Reuters on Thursday.

"The onslaught of threats against election workers is unacceptable and raises serious concerns about state and local governments’ ability to recruit and retain election workers needed to administer future elections," Democratic Senators Amy Klobuchar and Dick Durbin told the federal agencies on Wednesday in the previously unreported memo.

Klobuchar and Durbin were joined by 20 other Democratic senators asking the Department of Homeland Security and the Federal Bureau of Investigation to distribute a public service announcement to local and state police about increased threats against election workers, according to the memo.

"We have heard that in many cases when election officials report threats, local law enforcement agencies treat them as isolated incidents, instead of as part of a growing nationwide trend," the senators said.

A DHS spokesperson said it has enhanced collaboration with government partners by "sharing timely and actionable information" on threats. The FBI confirmed it received the memo.

At recent Senate hearings, elections officials have testified about a rise in threats following the 2020 election.

"These threats have continued against me and others," said Arizona Secretary of State Katie Hobbs, who was assigned a security detail after receiving a barrage of threats from supporters of former President Donald Trump. Election workers "are on the receiving end of abusive phone calls and emails" almost everyday, she said.

In a series of investigative reports, Reuters documented an unprecedented wave of terroristic threats against the frontline workers of American democracy, inspired by Trump's false claims that the 2020 election was stolen. In all, the news organization documented more than 900 threats and harassing messages against election administrators in 17 states.

After Reuters reported the widespread threats against election workers last June, the U.S. Department of Justice launched a task force to investigate threats against election staff. So far, the task force has announced two arrests.

In Wednesday’s memo, the senators also asked federal agencies to remind election officials of the federal resources available to them for reporting and mitigating threats. Last month, the Federal Election Assistance Commission voted to expand the use of federal money for election workers by allowing them to use funds for personal security services and social media threat monitoring.