Representative Jamaal Bowman, Democrat of New York, pulled a fire alarm in the House Cannon office building on Saturday as his party was trying to delay a vote on a stopgap spending bill, prompting an evacuation of the building and investigations by the Capitol Police and the House Administration Committee.

The alarm was triggered at the same time that House Democrats at the Capitol were stalling a vote on a spending measure to keep the government operating for another 45 days. Speaker Kevin McCarthy had unveiled the bill just minutes earlier, and Democrats were scrambling to read the bill and determine whether to support it. Later in the day, the bill passed 335 to 91, with more Democrats voting for it than Republicans.

In a statement released Saturday night, Mr. Bowman said that he had not pulled the alarm to delay the vote, as some Republicans had presumed. He said that as he was rushing to the Capitol to cast a vote, he came to a door in the Cannon building that 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,” Mr. Bowman said. “But I want to be very clear: this was not me, in any way, trying to delay any vote. It was the exact opposite — I was trying urgently to get to a vote.”

He added that he met with the sergeant-at-arms and Capitol Police after the incident at their request to explain what had happened.

The House Administration Committee began an inquiry on why the alarm was triggered, said its chairman, Representative Bryan Steil, Republican of Wisconsin, in a statement. The Capitol Police said the building was briefly evacuated. “An investigation into what happened and why continues,” a police spokesman, Paul Starks, said.

Republicans were quick to link the alarm to the vote on the spending bill. At a news conference after the spending measure passed, Mr. McCarthy criticized Mr. Bowman, suggesting he set off the alarm in an attempt to obstruct proceedings. “When we found that an individual elected to Congress would pull a fire alarm, that’s a new low,” he said.

Representative Nicole Malliotakis, Republican of New York, has drafted a motion to expel Mr. Bowman from the House, her office said.

“This is the United States Congress, not a New York City high school,” Ms. Malliotakis wrote on X. “To pull the fire alarm to disrupt proceedings when we are trying to draft legislation to AVERT A SHUTDOWN is pathetic.”