A girls rugby coach was beaten until he was bloody and unconscious during a weekend match, and police are seeking criminal charges against several adults.

"I never saw them coming," said Craig Stewart, 55, who was kicked in the head and face by another coach and parents during a game Saturday, according to witnesses and police.

The violence erupted during a tournament game between the Rohnert Park Girls Rugby Club (search) and Stewart's team, the Alameda High School Riptide (search) club team.

The conflict began when referee Paul Berman, 33, ordered a spectator off the field. He was punched in the face three times by the brother of the coach of the Rohnert Park team, police Sgt. Art Sweeney said.

Stewart intervened to help Berman and held the attacker on the ground until police arrived, detectives said. The Rohnert Park coach and up to eight spectators then descended on Stewart, Sweeney said.

Stewart was taken to Kaiser Medical Center in Santa Rosa with cuts and a head injury. He was recovering at home Sunday. Berman was treated on the scene for a split lip.

Several of the adults had fled by the time police arrived on the scene. Authorities were working to identify those involved in the fight. No one had been arrested by late Sunday.

Charges against the attackers could include battery and assault with a deadly weapon, Sweeney said.