With their ankle-length pioneer dresses and meticulously braided hairstyles, the mothers looked like they were waiting for the cameras to roll on the set of a Hollywood western. But for many of the 133 women, all members of a secretive and isolated polygamist sect, it was their first brush with the reality of the outside world.

Photo: Members of The Fundamentalist Church of Jesus Christ of Latter Day Saints are escorted onto a school bus in Eldorado, Texas

And with them were more than 400 of their children, all swept into custody from the sprawling Yearning for Zion Ranch in the Texas desert as part of an under-age sex probe. The day-long raid was sparked by a 16-year-old girl''''s call to police saying she was being abused and that brides as young as 14 and 15 were being forced into marriages with much older men.

She told police she had given birth to her 50-year-old husband's baby when she was just 15. Investigators had been unable to trace her by last night, but believe she may be among the children removed from the ranch.

Texas law does not allow marriage below the age of 16.

The men belonging to the sect, which promotes marriages to multiple wives, were being held at the 1,700-acre compound in the tiny west Texas cattle town of Eldorado while police carried out a house-by-house search. The mothers and their children were being held at a historic fort about 40 miles away.

For most of them, it was the first time they had talked to anyone outside the Fundamentalist Church of Jesus Christ of Latter Day Saints, a 10,000-member sect that broke away from the Mormon Church in the 1930s after it disavowed polygamy.

The group's self-styled prophet, Warren Jeffs, was jailed last year for being an accomplice in the rape of a 14-year-old girl who was forced to marry her 19-year-old cousin.

Jeffs, who took over leadership of the church on his father's death in 2002, was rumoured to have as many as 80 wives and 250 children and ruled the offshoot church with a rod of iron before his arrest in August, 2006.

Child protection social workers struggled to identify the women and their children in Texas, with many of them sharing the same names.The women milled about as their children played on the parade grounds of 150-year-old fort.

"This is a very strange situation for them," said one official. "They have been removed from a very isolated community." Until Friday's raid on the compound, the women spent their days tilling the fields, quilting and hand-sewing their own clothes.

Photo: Spiritual leader: Warren Jeffs is currently in jail in Arizona

But investigators say it was no idyllic recreation of 19th century prairie life. They fear the mothers stood by as fathers preyed on the younger girls. Behind a double gate five miles off the nearest main road, the ranch has its own temple, a doctor's office, a school, a cement plant and a cheese-making factory.

"Once you go into the compound, you don't ever leave it," said Carolyn Jessop, who was one of t