A man whipped himself until he bled during a Shia Muslim religious ceremony, before allegedly forcing two boys to do the same, a court has heard.
Syed Mustafa Zaidi, 44, is accused of encouraging the boys, aged 13 and 15, to beat themselves at a community centre in Manchester on 19 January.
Manchester Crown Court was played a film showing Mr Zaidi beating himself with a whip made of knives and chains.
Mr Zaidi, of Station Road, Eccles, denies two counts of child cruelty.
It is the first case of its kind ever to be prosecuted in the UK.
The 20-minute video shown to the court showed the Shia Muslim Ashura ceremony in Levenshulme, with Mr Zaidi bare-chested among a crowd of about 150 men, chanting and singing.
He then used the whip - called a zanjeer - on himself.
Participants at the men-only event take it in turns, in small groups, to flog themselves, while the crowd around them chant the name of Husayn, a central figure in the Shia faith whose death they are commemorating.
The film played to the court also showed the 13-year-old boy, who Zaidi is accused of forcing, flogging himself with the whip.
Prosecutors said the 15-year-old boy, who is not seen in the film but was allegedly forced to take part in the ceremony, suffered multiple lacerations to his back and shoulders, including a wound measuring up to a centimetre long.
Andrew Nuttall, prosecutor, said Mr Zaidi also harmed himself in the film.
"This devout man used considerable force upon himself, clearly causing injuries, and causing others present to fear for his safety to such an extent that they started to intervene and calm him down," he said.
Mr Nuttall said Mr Zaidi then went on to encourage the 15-year-old boy to flog himself and gave him "no choice" about participating in the ceremony.
He said Mr Zaidi took the arm of the 13-year-old boy, took off his T-shirt so he was bare-chested and put the zanjeer in his hand and told him to flog himself.
'Not for children'
The court heard how Mr Zaidi had attended a meeting at the community centre two days before the ceremony, where it was made plain that children under the age of 16 should not participate.
Mr Zaidi denies forcing the boys to participate and claims they had requested to take part.
Mr Nuttall said: "The prosecution say the defendant ignored the advice given to him that this practice was not allowed for children under 16 years of age."
He said Zaidi forced the boys to participate in a ceremony "clearly designed to cause self harm".
Mr Nuttall added: "This was not only against their own will but in any event is not allowed by law."
The case continues.