A left-wing Jewish group occupied one of the buildings in the U.S. Capitol complex on Wednesday, calling for a ceasefire in the ongoing war between Israel and Hamas.
The demonstrators entered the building at different security entrance points and then assembled in the Cannon House Office Building rotunda.
More than 100 people had gathered in the rotunda and were protesting when authorities began to detain them.
Police did not have an immediate estimate on how many protesters who occupied the building were then detained.