Michigan Secretary of State Jocelyn Benson says armed demonstrators gathered outside her home to protest against alleged election fraud.
She said “dozens” of people arrived at her home on Saturday evening as she was putting up Christmas decorations with her son.
Protesters shouted “stop the steal!”, echoing claims of voter fraud made by President Donald Trump.
Attorney General William Barr has said there is no proof to back these claims.
Ms Benson has joined a growing number of government and election officials targeted by protesters this year over the 2020 election.
In a statement posted to Twitter on Sunday, Ms Benson, a Democrat, said that protesters made “unambiguous, loud and threatening” demands outside her Detroit home to overturn the state’s election results.
Michigan last month certified its results, declaring Democrat Joe Biden the winner of the state’s 16 electoral votes.
Part of the demonstration was streamed live on Facebook.
“We are not standing down, we are not giving up, you are not going to take this election from a man that has earned it completely 100% by a freaking landslide,” said Genevieve Peters, who posted the video.
Police responded to a public disturbance call around 21:50 EST (01:50 GMT), local media said, and the crowd dispersed shortly after. A local police chief said he also thought some of them were armed.
No arrests were made. It is not a crime to carry a firearm in Michigan, as long as the weapon is legally owned and not concealed.
In a statement, Michigan’s Attorney General Dana Nessel and Wayne County Prosecutor Kym Worthy described the incident as “disturbing behaviour masquerading as protest”.
“Anyone can air legitimate grievances to Secretary Benson’s office through civil and democratic means, but terrorising children and families at their own homes is not activism,” they said.
In her own statement, Ms Benson appeared to tie the protest outside her home to ongoing efforts by Mr Trump and his legal team to overturn the results of the presidential election – citing “purely political legislative hearings” and “bogus legal claims”.
Mr Trump has so far refused to concede the election and has launched a series of legal challenges alleging, without evidence, that Mr Biden’s win was the result of fraud.
Last week an election official in Georgia, Gabriel Sterling, warned that President Trump was inciting violence, citing death threats made to staff.
In Arizona, Secretary of State Katie Hobbs said last month that her family had received “utterly abhorrent threats”.