SPOKANE, Wash. — Four members of a Polish death metal band arrested on charges of kidnapping a Washington state woman are also suspected of sexually assaulting her after a concert during a party on the band's tour bus, according to court documents.

The documents made public Monday said the assault by the members of Decapitated happened in the bathroom of the tour bus following the Aug. 31 concert in Spokane, Washington.

The band members were arrested Saturday in Santa Ana, California, for investigation of first degree kidnapping. The four men appeared in court in Los Angeles Tuesday and waived extradition to Washington, KABC-TV reported.

Steve Graham, a lawyer for the band members, said in an email that the members of "Decapitated plan to fully fight the allegations that have been brought against them and are confident that their side of the story will be heard."

Decapitated had been touring with the Australian band Thy Art is Murder, and performed several shows after the Spokane concert before being arrested.

Arrested were band members Michal Lysejko, 31; Waclaw Kieltyka, 35; Rafal Piotrowski, 31; and Hubert Wiecek, 30.

The woman and her friend told Spokane police they attended the Aug. 31 show, spoke with members of Decapitated and were invited to have drinks in the tour bus. Once on the bus, the women reported they began to feel uncomfortable.

One of the women went to use the bathroom on the bus and was followed inside by a band member, according to the documents filed by police in Spokane County Superior Court.

The woman tried to push him away, "but he grabbed her arm and spun her around to where she was facing the sink and mirror in the bathroom," court documents said.

"She saw in the mirror and out of the corner of her eye each of the band members taking turns raping her," the documents said.

The woman's friend told police in the documents that she watched the band members commit the assault.

The woman said a band member helped her get dressed and carried her out of the bus before she walked away and called 911.

A police officer who picked her up returned to the concert venue, but the tour bus was gone.

The documents said the woman was examined at a hospital where she was found to have upper arm bruises consistent with being restrained and other injuries.

Graham, the band's attorney, told The Spokesman-Review newspaper, "We have witnesses that can testify to the fact that the accuser came to visit the band of her own free will and left on good terms."

Band members were interviewed Thursday by sheriff's detectives.

Lysejko told officers he did not know the women when shown a picture of her. Kieltyka said he saw two members of the band engage in sex acts with the woman in the bus bathroom, the court documents said.

Piotrowski said the women were at a party on the bus but declined additional comment, while Wiecek said the two women had been on the bus but he did not see what was going on, court documents said.

The women were not identified in the court documents.