Dozens of women stopped for minor traffic violations and other petty offenses have been forced by police here to strip and have their genitals examined for hidden weapons and drugs, the American Civil Liberties Union has charged.

While most of the strip searches have been conducted by matrons in police lockups, some have occurred in homes, on the street and with male police personnel looking on, ACLU officials alleged Tuesday.

The organization said that it would file a class-action suit against the city of Chicago and its Police Department asking $1 million in damages for any woman illegally strip searched.

Police Supt. James O'Grady said that he was not surprised by the allegation because complaints about strip searches have occurred with almost daily frequency.

"We've had these complaints over the years," O'Grady said. "We've investigated them, we have taken action on them, we've had lawsuits against us for violations of cases such as this."

He said that state rules require all persons taken into custody to be searched. However, he added, the Police Department does not do blanket searches but uses its discretion.

The police Internal Affairs Division, the U.S. Attorney's office in Chicago and the FBI have begun investigations into the allegations.

Jay Miller, executive director of the Illinois chapter of the ACLU, called the searches "illegal and outrageous harassment," and urged the police to halt the practice immediately.

"What the police are doing to women is crude and ugly," Miller said. He asserted that many of the searches were conducted by unqualified personnel in unsanitary surroundings.

The charges came in the wake of a report aired Monday night by a television station outlining the experiences of several women who were stopped for minor traffic infractions.

Typical of their stories was the one from a college student identified in the report only as Miss Y. She had been stopped for making an illegal left turn and had left her driver's license at home. As a result, police directed her to follow them to the 19th District station house.

Miss Y told reporter Jim Ruddle that she was taken into a room with cells and closed-circuit TV cameras. She said she balked at first, but the matron with her was insistent.

"I explained to her that all I had done was make an illegal left turn," Miss Y told Ruddle. "I am not here because I robbed somebody.

"So she [the matron] said it again -- lift your shirt, and I did that. Then I thought it was over. It wasn't."

Miss Y said that the matron then ordered her to remove the rest of her clothing, squat and expose her genitals.

"Had you been charged with any serious offense at that time?" Ruddle asked. "Nothing," she responded. "No rights were read to me. They didn't tell me I was arrested. And then finally I asked them -- you know -- am I here because I made a lefthand turn on Belmont? And they said 'Yes'"

Her traffic ticket was later dismissed in court, the television report said.

Both the television station and the ACLU said that their offices were flooded with calls from women alleging they had been the victims of similar incidents.