Nine protesters were arrested Tuesday at the Charleston office of Senator Joe Manchin, Democrat of West Virginia, during a sit-in urging him to vote against the Supreme Court nomination of Judge Brett M. Kavanaugh.

The protesters arrested at 12:45 a.m. on Tuesday were the remnants of a larger group of 18 women who arrived at the senator’s campaign office at 2 p.m. on Monday, according to the Democratic Socialists of America, whose members in West Virginia helped to organize the demonstration.

They had spent the day on Monday broadcasting their sit-in on social media, sharing their stories of sexual violence and encouraging people to donate to REACH, a local organization that provides free counseling services to victims of sexual abuse.

The Manchin campaign said it eventually asked the protesters to leave the office “after a long discussion” but had not asked for them to be arrested.