ELDORADO, Texas (CNN) -- Authorities say they removed 52 children, ages 6 months to 17 years, from a West Texas ranch occupied by followers of imprisoned polygamist sect leader Warren Jeffs.

Texas authorties stand in front of a bus they used to transport children from a FLDS compound Friday.

Eighteen girls have been placed in the temporary custody of the state under a court order, said Child Protective Services spokeswoman Marleigh Meisner.

Authorities said they continue to search the 1,900-acre YFZ ranch, and at least one suspect is being sought by police.

Meisner said troopers and child welfare officials arrived at the secluded ranch Thursday evening with arrest and search warrants. They were responding to a report of "physical abuse" and neglect involving a 16-year-old girl.

Another Child Protective Services spokesman, Darrell Azar, said the 18 girls were placed in state custody because it appeared they "had been abused or were at immediate risk of future abuse." Watch buses take girls from compound »

Law enforcement and child welfare officials were at the ranch all night Thursday and throughout Friday. Meisner said the search was expected to continue into the night.

No arrests had been made by early Friday evening, a Texas Department of Public Safety spokesman said in a recorded message.

According to the search warrant, authorities are seeking Dale Barlow, 50, who they suspect of having married and fathered a child with a 16-year-old girl.

Law enforcement agencies raided the ranch Thursday night after receiving a Monday report that a 16-year-old girl had been "sexually and physically abused," said Azar. Watch an Eldorado neighbor talk about the raid »

The warrant cited an "immediate need" for authorities to have access to the 16-year-old and an 8-month-old child with either the last name of Barlow or the girl's last name. It instructs law enforcement officers to look for any records showing Barlow and the girl were married and any evidence of them having a child.

The children were taken in two borrowed church buses from the ranch to a civic center near Eldorado.

The people living at the ranch are cooperating, authorities said.

Jeffs, the 52-year-old leader and "prophet" of the 10,000-member church, was convicted in Utah last year and sentenced to 10 years on two counts of being an accomplice to rape, charges related to a marriage he performed in 2001. He faces trial in Arizona on eight charges of sexual conduct with a minor, incest and conspiracy.

Jeffs' Fundamentalist Church of Jesus Christ of Latter Day Saints bought the land near Eldorado four years ago and built the ranch, which they call the YFZ Ranch. The letters are said to refer to the words Yearning for Zion.

It is home to as many as 400 members who relocated from their Arizona and Utah compounds.

State and local law enforcement agencies set up roadblocks around the ranch Thursday evening, preventing journalists from seeing what was happening on the property, according to Randy Mankin, editor of the Eldorado Success weekly newspaper.

"This came totally out of the blue," Mankin said.

There were no indications of violence around the ranch, he said.

When CNN crews have visited the ranch, it was guarded by armed men equipped with night vision gear and other high-tech surveillance tools to prevent intruders.

When CNN flew over the ranch in a small plane last year, the crew saw a massive temple, the three-story housing units where Jeffs' chosen followers live, the water tower, the school and community center, the dairy and cheese factory and a massive concrete mill.

The church openly practices polygamy in two towns straddling the Arizona-Utah state line -- Hildale, Utah, and Colorado City, Arizona -- but members living on their Texas ranch rarely venture into Eldorado, four miles to the south.

Critics of the sect say that it arranges marriages for girls as young as 13 and that competition for brides may be reduced through exiling young men. If male followers are excommunicated, the critics claim, their wives and children can be reassigned to someone else.