Teachers at Christian fundamentalist schools in Britain allegedly performed exorcisms on pupils, beat children in religious rituals and “groomed” girls for marriage, according to former students who say they have decided to speak out now after years of suffering in silence.

The former pupils told The Independent such treatment of children was a “terrifying” part of life at schools in the 1980s, 1990s and early 2000s in an environment where they felt too afraid to complain for fear of retribution from school staff, evangelical parents and their close-knit Baptist faith community.

One former pupil alleged that in the 1990s pupils at school assemblies would start convulsing amid “blood curdling screams” as prayers were said for the holy spirit to rid children of demons. The alleged abuse is said to have taken place many years ago at a number of schools in the UK that follow the Accelerated Christian Education (ACE) curriculum, a form of learning that originated in the southern Baptist states of the US.

The former pupils contacted The Independent after reading our June report revealing that some of these schools still teach children that girls must submit to men, homosexuality is unnatural and that creationism is a fact. They said the article jolted their memories of their own experiences.

More than 1,000 4-18 year olds are currently taught in 30 ACE schools in the UK, all of them registered as private institutions. Although the schools are bound by the same safeguarding and child protection regulations as the state sector, former pupils want assurances that monitoring of these schools is more effective than when they attended.

One told The Independent that during his time at an ACE school in the 1990s: “We were told that we were the children of God and the world was out to get us. So we were isolated and couldn’t speak out. There was nobody checking on us. I just took it.”

Pupils who have traditionally attended the schools tend to come from Christian families who follow a fundamentalist interpretation of the Bible. Former pupils said many of the children will have limited interaction with mainstream society.

One former pupil, who attended a school in the 1990s and who has asked not to be named, said: “Exorcisms used to happen at school assemblies sometimes. There would be 20 or so children and perhaps five adults. We were told that the holy spirit would come through children. I started convulsing and I couldn’t stop. Even when I went to bed I kept convulsing. I was terrified, I really thought it was the holy spirit.

“We would all begin convulsing. I remember them screaming blood curdling screams and then we’d all pray rigorously to get the demons out. Teachers would physically push us. They’d lay their hands on us when we prayed and they’d push us down. If you didn’t fall it was said that you weren’t really ‘feeling the Lord’. It was a very dark thing. It really was insanity. It got completely out of control.”

Two other former pupils from the 1990s and 2000s alleged they witnessed exorcisms performed on some occasions at other schools, where children were encouraged to “speak in tongues”.

Allegations from ex-pupils include other potential concerns. At some schools, girls were groomed for marriage from a young age, two former students said. They claimed the grooming was done by the church communities that run the schools and by teachers. Methods were said to include controlling girls’ sexuality and isolating them from boys their own age so they might later be married to much older male members of the church groups.

In some schools they were allegedly encouraged to marry soon after they turned 16, as church leaders told them it was “God’s will”.

One woman, who attended a school between the late 1990s and early 2000s, said: “There was one girl I knew who married someone more than 20 years older. The man she married had known her since she was seven years old and he was 30. She’d sit on his knee when she was a child. He’d played with her when she was a child. Now they’re married. It’s just really creepy.

“As a young girl, you were told you were not allowed to talk to boys your own age, you had to stand six inches apart from boys at all times at schools, teachers told you they’d hit you with a wooden paddle if you kiss a boy. So you didn’t get to meet anyone else and then you’re shown sexual interest for the first time and it’s some creepy old man. It was so sexualised, they were sexualising children.”

Another former pupil who attended an ACE school in the 1990s said a girl at her school had married a man at 16, when he was in his 40s, and who she had met when he began teaching at her school.

She said: “You were told from a young age that your role is to support a man and God will lead you to him. The role of women in these religious groups is quite clear. You’re told God has chosen a husband for you and God will lead this man to you. But in reality, pastors and church leaders guide men to you. It’s grooming.”

She added: “When I was 18, I experienced it. From the age of 14, the church had been pushing me towards a man in the church group who was eight years older. I was actively encouraged to work with him. They were very pushy about marriage, it was very intimidating. It’s very closed and isolating.

“As a girl, you’re left feeling redundant if you don’t get married. You’re told it’s God’s will and you’re just wasting time until you get married – it’s your ultimate goal.”

She said that none of the girls married before the legal age of consent, adding: “They are very keen to ensure nothing illegal happened, but the conditioning was around a long time before that.”

Although all the claims made by former pupils for this article relate to historic incidents, textbooks still used by the schools – and seen by The Independent – raise current concerns.

The books suggest pupils are still taught that “the wife is to obey, respect and submit to the leadership of her husband, serving as a helper to him” and “God desires for [women] to submit to husband.”

Other pupils told The Independent there were also historic concerns about corporal punishment, which they say took on a religious characteristic at the ACE schools.

They claimed children were beaten with a wooden paddle and then forced into a ritualised religious quasi-ceremony in which prayers were said for their salvation in the 1980s and 1990s. They said that the church groups believed at the time that corporal punishment was “God’s will” as it stopped children from sinning.

Corporal punishment was outlawed in UK private schools in 1998 and there is no suggestion the ACE schools breached that law.

David Waldock who attended an ACE school between the ages of 11 and 16 prior to 1998 said: “I was beaten with a cane by teachers while a pupil at an ACE school. The school was in the basement of the church. The cane was kept in the vestry. You would be led up to the vestry to a fold down desk, inside was a cardboard case and in that was the cane.

“The teachers explained to you your ‘offence’. You were told to take your trousers down. Then you were bent over a chair with your trousers down and wearing just your underwear. Then you were caned. And then you prayed for forgiveness.

“It was very ritualised. It was a ritual of confession, administration and prayer for forgiveness.”

One former pupil who attended an ACE school in the 1990s said a four-year-old boy at her school had special needs which caused him to urinate and defecate uncontrollably in class. She claims the child would be routinely taken to be beaten by the headmaster with a wooden paddle to punish this “bad behaviour”.

She says knowing corporal punishment was happening to other children was extremely distressing: “I remember feeling sick. I was so frightened I dug my nails into my hands.”

A 1993 copy of the ACE teachers’ training manual, seen by The Independent, appears to instruct teachers in how to administer corporal punishment when children have “sinned” in ritualised religious ceremonies. It says: “Demerits are for procedural violations; the paddle is for moral violations.”

The manual then lists a step by step process for hitting children.

“Using Bible verses, explain to the child the principles he has violated. Make sure he clearly understands what he has done wrong — position the child so he is leaning forward with his hands on a desk or chair and with his feet spread. Keep the paddle, switch, or belt low to avoid hitting the spine.

“Pray with the child following corporal correction. Review the offense and show him Hebrews 13.17. Request that he ask the Lord to forgive him for _____ (name the violation) and help him obey God’s Word and those people God has placed in his life to train him.”

An updated edition of the teacher training manual compiled after 1998 stops advocating corporal punishment by teachers at ACE schools. Christian Education Europe, an organisational body that runs and promotes ACE schools, say stocks of teaching manuals are regularly checked to ensure they are up to date.

A former pupil who attended an ACE school in the 1990s said: “The kind of people who send their children to schools like these believe in it absolutely. The pastor had absolute power and they could do anything.”