The U.S. Forest Service says about 400 members of the Rainbow Family threw rocks and sticks at federal officers who were trying to arrest a member of the group.

The agency says five members were arrested and one officer was slightly injured.

About 7,000 members of the Rainbow Family have gathered on federal land near Big Piney. The Rainbow Family is a loose affiliation of eccentrics, young people and hippie types who choose a forest each year in which hold a weeklong national gathering.

U.S. Forest Service spokeswoman Rita Vollmer says 10 Forest Service officers were patrolling the main meadow of the Rainbow Family’s camping area on Thursday night. She says a mob of Rainbow Family members confronted the officers as they tried to detain one person the agency describes as being uncooperative.