Republicans are working to expel a US congressman accused of pulling a fire alarm to delay a crucial vote in the House of Representatives.
New York Democrat Jamaal Bowman said he activated the alarm by mistake on Saturday while rushing to a vote.
It went off as Democrats were trying to stall a vote on a stopgap funding bill keep the federal government operating and avert a shutdown.
The alarm triggered an evacuation and police investigation.
On Monday, Congresswoman Nicole Malliotakis formally introduced a resolution, backed by 12 other Republicans, to expel her fellow New Yorker from Congress.
"Mr Bowman's juvenile actions violated both federal and local law and he must be held accountable," she said.
Expulsion from the House requires two-thirds of the chamber in support, a high bar in a chamber that Republicans only narrowly control.
Officers said they evacuated the Cannon House Office Building, which contains the offices of several House of Representatives lawmakers, after the fire alarm went off.
"On security video, a man was seen trying to exit the door in the Cannon Building and then pulling the fire alarm that prompted the evacuation," a police statement said on Monday.
The statement added that "officers had previously placed signs with clear language that explained the door was secured and marked as an emergency exit only".
The alarm went off as the House of Representatives was set to vote on a last-minute funding measure to keep the government open and avert a shutdown.
Democrats had been seeking to buy more time ahead of the vote, complaining they had not had enough time to read the bill.
Pulling a fire alarm when there is no emergency is a criminal offence punishable by fines and prison time in Washington.
After Mr Bowman's office confirmed he had set off the alarm, Republicans launched their own investigation into his actions, with Speaker Kevin McCarthy calling it "a new low".
In a statement on Saturday, Mr Bowman wrote: "Today, as I was rushing to make a vote, I came to a door that is usually open for votes but today would not open.
"I am embarrassed to admit that I activated the fire alarm, mistakenly thinking it would open the door. I regret this and sincerely apologize for any confusion this caused."
"I want to be very clear, this was not me, in any way trying to delay any vote," the left-wing Democrat from the Bronx added. "My hope is that no-one will make more of this than it was."
But in a post on X, formerly known as Twitter, Ms Malliotakis pointed out that the second-term lawmaker had been a middle school principal before he entered politics.
A handbook for the Cornerstone Academy for Social Action, the school founded and led by Mr Bowman, mandates suspension or expulsion for falsely setting off fire alarms.
On Monday, the congressman was back in damage control mode over a related controversy after Politico shared a memo his office had sent out to fellow Democrats asking them to defend him.
One of the document's suggested talking points reads: "I believe Congressman Bowman when he says this was an accident. Republicans need to instead focus their energy on the Nazi members of their party before anything else."
Mr Bowman posted on X that the term Nazi had been used "without my consent".
"I condemn the use of the term Nazi out of its precise definition," he wrote. "It is important to specify the term Nazi to refer to members of the Nazi party & neo-Nazis."
