LOS ANGELES — Nearly 100 women who contend that they were sexually harassed or abused by a former University of Southern California gynecologist are suing the school, contending it ignored decades of complaints.

"I am part of an accidental sisterhood of hundreds of women because the university we love betrayed our trust," said Dana Loewy, who alleged that Dr. George Tyndall assaulted her during an examination in 1993.

She was among some 20 women who appeared at a news conference Thursday to announce the filing of new lawsuits on behalf of 93 women against the university.

About 500 current and former students have now made accusations against Tyndall. They contend he routinely made crude comments, took inappropriate photographs and forced plaintiffs to strip naked and groped them under the guise of medical treatment. Complaints reportedly go back as far as 1988.

Attorney John Manly noted that Los Angeles police and the Los Angeles County district attorney's office both are reviewing allegations against Tyndall. But he called on the state attorney general's office to investigate USC's handling of complaints against Tyndall.

Dr. George Tyndall.

"The University of Southern California, my alma mater, is the recipient of hundreds of millions of dollars of state of California aid, and it is clear they miserably failed these women," he said.

Brennan Heil, a USC senior, said she went to see Tyndall as a freshman after she was raped.

"During the consultation, he molested me," she alleged during the press conference.

Two women said they called USC's hotline to report complaints against Tyndall but received no follow-up.

Manly accused USC's Board of Trustees of failing to speak out about the alleged abuses. He specifically named some of the high-powered members, including Steven Spielberg, United Airlines CEO Oscar Munoz and Los Angeles Lakers owner Jeanie Buss.

"They haven't said a word. Not one," he said. "All these women: 500. You're on the board. Say something."

In a statement, USC said it was aware of the lawsuits and will seek "a prompt and fair resolution that is respectful of our former students."

Tyndall spent about three decades as a USC staff gynecologist before retiring last year after a USC investigation concluded that there was evidence that Tyndall sexually harassed students during physical examinations.

Tyndall has denied the allegations and has not been charged with a crime. USC has denied accusations of a cover-up.

In August, USC President C. L. Max Nikias stepped down in the wake of the criticism arising from the sex-abuse allegations.