Nine protesters were arrested by the U.S. Capitol Police on Friday afternoon after they interrupted the budget debate by singing loudly from the House visitors’ gallery.

The protesters were charged with unlawful conduct, according to Sgt. Kimberly Schneider, a spokeswoman for the U.S. Capitol Police. As of Friday afternoon, the protesters were being processed at Capitol Police headquarters.

It was not immediately clear whether the protesters were part of an organized group. They appeared to be environmentalists protesting the fiscal 2012 budget, which the House approved later Friday afternoon.

“We want the government to protect our futures and not the futures of the corporations,” one protester said to reporters as a Capitol Police officer put her in flexicuffs in the third-floor hallway outside the House chamber. About five other protesters alongside her were also being cuffed.

Asked whether the protesters were part of an organized group, the girl responded, “No, we’re just people.”

The protest came as the House rejected a Democratic budget alternative and was beginning debate on the budget plan proposed by Rep. Paul Ryan (R-Wis.), which was expected to pass the House later Friday.

As Rep. Chris Van Hollen (D-Md.), the ranking Democrat on the Budget Committee, was speaking on the House floor, the first protester stood in the visitors gallery overlooking the chamber and began singing what sounded like the National Anthem, only with altered lyrics.

“Oh, say, can you see that our earth is at stake?” the protester sang; the rest of the words were unclear to reporters listening from the opposite gallery.

The protester was escorted out of the gallery. A few minutes later, as the debate on the floor continued, a second protester rose in the visitors gallery and began singing. That protester, too, was escorted out and into the hallway.

Lawmakers appeared to grow impatient with the disturbances, with several in the chamber yelling, “Clear the gallery! Clear the gallery!”

After a few more protesters interrupted the debate, Van Hollen and Ryan huddled with other lawmakers near the well of the House to determine their next step.

A few minutes later, they proceeded with debate. Then another protester stood in the gallery, with his fist raised, singing, “We Shall Overcome.” After that protester was escorted out, another stood and began singing.

C-SPAN has video.

This post has been updated since it was first published.