ELDORADO, Texas (CNN) --
Police escort church members off a school bus Saturday night in Eldorado, Texas.
1 of 4 Police called in ambulances and other emergency vehicles as they prepared to search the polygamist group's temple, officials said.
Authorities wanted medical backup "in case they're involved in sensitive areas that could escalate into a negative reaction," a law enforcement source said. A police helicopter circled the ranch Saturday night.
The Fundamentalist Church of Jesus Christ of Latter Day Saints is a rogue branch of the Mormon church and forbids nonbelievers from entering its temples.
There were no immediate reports of injuries or arrests at the compound.
Earlier Saturday, 131 children and young women were removed from the ranch, bringing the total of people removed from the ranch to 183 since law enforcement officers raided the compound Thursday.
The majority of the 137 children removed from the ranch were girls. About 40 boys were removed, said Marleigh Meisner, a spokeswoman for the Texas Child Protective Services.
"We're trying to find out if they're safe," she explained. "We need to know if they have been abused or neglected."
Eighteen of the girls, who the state believes "had been abused or were at immediate risk of future abuse," were taken into state custody, Child Protective Services spokesman Darrell Azar said.
The others were taken to a nearby civic center where they are being questioned about abuse.
Warren Jeffs, the 52-year-old leader of the 10,000-member church, was convicted in Utah last year on two counts of accomplice to rape, charges related to a marriage he performed in 2001. He still faces trial in Arizona on eight charges of sexual conduct with a minor, incest and conspiracy.
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. Watch buses take girls from compound »
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.
The church bought 1,900 acres near Eldorado four years ago and built what it calls the YFZ Ranch. It is home to as many as 400 members who relocated from their Arizona and Utah compounds.
YFZ is a reference to a song written by Jeffs, "Yearning For Zion."
Previous visits by CNN revealed the ranch was guarded by armed men equipped with night-vision gear and other high-tech surveillance tools to prevent intruders from entering.
Ambulances entered the ranch about 7 p.m. No one had been injured and there had been no violence when they arrived, the sources said.
Law enforcement agencies and four agents from Child Protective Services continued to search the compound late Saturday.
A warrant was served Thursday night for Dale Evans Barlow, 50, who authorities believe fathered a child with a 16-year-old girl that he married.
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 that Barlow and the girl were married and any evidence of them having a child.
As of Saturday night, Barlow had not been located and child welfare workers could not confirm whether the girl or her child had been found.
Barlow is in Arizona and does not know his accuser, his probation officer told The Salt Lake Tribune.
"He said the authorities had called him [in Colorado City, Arizona], and some girl had accused him of assaulting her, and he didn't even know who she was," Bill Loader said.
Barlow pleaded no contest last year to conspiracy to commit sexual conduct with a minor, The Associated Press reported.
He was ordered to register as a sex offender for three years, according to the AP.
His lawyer in that case told AP he had not spoken to Barlow in a year