CHEYENNE, Wyo. (AP) About 400 members of the Rainbow Family threw rocks and sticks at ten federal officers on Thursday night as they tried to arrest one member of the group at its annual gathering in western Wyoming, the U.S. Forest Service reported. The agency said five members of the group were arrested and one officer was injured slightly.

About 7,000 members of the Rainbow Family are camping this year on Forest Service land near Big Piney, in Sublette County. The group camps at a different place on federal lands each year around the Fourth of July holiday.

Rita Vollmer, spokeswoman for the U.S. Forest Service, issued a statement Friday morning saying that 10 Forest Service officers were patrolling the main meadow of the Rainbow Family's camping area on Thursday night. She said the officers apprehended one person described as being uncooperative.

''Officers began to leave the gathering site with the subject and were circled by more Rainbow participants that began to physically interfere,'' Vollmer stated. ''Another participant was detained for physical interference.''

As the ten officers were taking the two people out of the area, ''about 400 Rainbows surrounded the squad trying to leave,'' according to the statement. ''More officers were requested to assist in the main meadow area. The mob began to advance, throwing sticks and rocks at the officers. Crowd control tactics were used to keep moving through the group of Rainbows.''

The statement quotes Forest Service Director of Law Enforcement John Twiss as saying, ''This lawless behavior is unacceptable and we will not tolerate it. The safety of our employees, public and Rainbow participants is our number one priority and we will continue to protect everyone on the National Forest.''

According to the statement, five people were arrested in the incident. One officer suffered minor injuries and was treated and released at a local hospital. A government vehicle also was damaged.

Attempts to reach Vollmer for information about the identity of those arrested and the charges against them weren't immediately successful on Friday.

Sgt. Stephen Townsend of the Wyoming Highway Patrol said Friday that state troopers were called to assist the federal officers and were on their way to the scene when they were informed they were no longer needed.

Townsend said state officers have issued some misdemeanor citations to members of the Rainbow Family charging them with possession of marijuana. He said two people were arrested this week on felony drug charges for allegedly possessing 96 hits of LSD.

Members of Wyoming's congressional delegation wrote to Agriculture Secretary Ed Schafer last month asking the U.S. Forest Service to do more to address frustrations about this year's Rainbow Family gathering.

Rep. Barbara Cubin and Sen. John Barrasso, both Republicans, raised concerns in separate letters to Schafer. They pointed out that because of the gathering, the Boy Scouts had to cancel a fence-removal project scheduled for a nearby area.