SAN FRANCISCO (Reuters) - Michigan’s Democratic governor has urged Facebook Chief Executive Mark Zuckerberg to step up efforts to check hate speech on the social network and protect the security of elections, citing attacks on legislators from the state.

FILE PHOTO: Rep. Rashida Tlaib (D-MI) participates in a House Financial Services Committee hearing with Facebook Chairman and CEO Mark Zuckerberg in Washington, U.S., October 23, 2019. REUTERS/Erin Scott

“Of late, hundreds of vitriolic, sexist and violent posts on Facebook have called for violence against Muslims and Michigan legislators,” Governor Gretchen Whitmer wrote to Zuckerberg in a letter she also shared on Twitter on Friday.

“For example, users have called for certain female, congressional leaders from my state to be ‘burned and raped,’ needing of a ‘bullet between her eyes,’ or instead, just ‘set ... on fire,” she said.

Facebook, in a statement, said it had been in contact with Whitmer’s office to address her concerns.

“Facebook prohibits hate speech and anything that incites or advocates for violence. While we take action against this type of content - in most cases before it’s reported - even a single piece that’s posted is too many. We appreciate Governor Whitmer bringing this to our attention,” the statement said.

Michigan congresswoman Rashida Tlaib, who is Palestinian-American, has been the frequent target of online harassment and racist slurs. Last year, she read aloud in Congress one death threat she had received.

The threats Whitmer cited appeared to come from a Facebook group, "People vs Gov. Gretchen Whitmer," exposed by Detroit local news group the Metro Times here.

Tlaib was the most common target of vitriol in the group, which had nearly 9,000 members before it was shuttered, although users also posted graphic death threats against Whitmer and U.S. Representative Elissa Slotkin, the Metro Times reported.

Whitmer said in her letter that the attacks were violations of Facebook’s own community standards and called for better enforcement of those rules ahead of this year’s election cycle.

“Mr. Zuckerberg, this country has been good to you, and history is knocking on your proverbial door. Are you prepared to rise to the occasion ... to protect our democracy from ongoing attacks?” she wrote.