The FBI said today that at least 11 people face kidnaping and extortion charges in the abduction of two sisters who are from Sterling, Va.

Among those arrested were the women's mother and her second husband.

According to an account published by the Detroit Free Press, Betsy Chase, 21, and her sister, Whitney, 18, reportedly had been detained and forced to undergo "deprogramming" in a home in Bloomfield Township, a wealthy Detroit suburb, over the Christmas holidays.

"It's a very complicated case," said FBI special agent Ralph Kush. "It wasn't really religious deprogramming. It was more trying to alienate one against the other. It was a marriage breakup-type situation."

An FBI spokesman said the sisters failed to return on schedule Dec. 28 to the home of their father, identified by the newspaper as Anthony Chase of Sterling.

Shortly thereafter, the spokesman said, Lawrence Iron Moccasin, 25, of Minneapolis, telephoned the fiance of one of the sisters and demanded that $5,000 be delivered to a contact in Minneapolis in exchange for their safe return.

On New Year's Eve, FBI agents in Minneapolis arrested Moccasin's sister-in-law in connection with the matter. A few hours later, FBI agents and local police searched a Bloomfield Township home, released the two sisters unharmed and arrested 10 other persons.

The FBI did not immediately release the names of the other suspects, but Bloomfield Township police said that among them were the women's mother, Karen Larson, 42, and her husband, Robert, 48. They were held in the Oakland County, Mich., jail.

Moccasin was held in lieu of $20,000 bail, the FBI said.