A "bullying" imam who "assaulted many children" and left them "writhing in pain" has been jailed.
Abdul Rauf, of Sussex Street, Rochdale, attacked two boys, aged 10 and 12, at a mosque study class in Greater Manchester in 2017, police said.
Reviewing CCTV footage, officers then found the 51-year-old had beat other pupils' "ears, arms and legs".
Admitting 21 assaults, he was jailed for 17 months at Manchester Minshull Street Crown Court.
'Intimidated and afraid'
A Greater Manchester Police spokesman said only the attack in October 2017 had been reported, but the CCTV evidence had allowed the force to charge the imam with further offences.
Speaking after sentencing, Insp Phil Key said Rauf was a "nasty bully of a man, who beat the children in classes until it became normalised".
"The parents had no idea that they were leaving their children in the care of a man who would leave them writhing in pain and covered in marks and bruises," he said.
"Rauf left the children intimidated and afraid to tell about his bullying tactics."
He added it was not known "how many children's lives he has affected over the years", and said police were working with the local council and mosque association to "ensure that this type of behaviour is never repeated".
A council spokesman said it had already "helped a number of groups establish effective safeguarding procedures" and was "working with many unregulated groups to inform them of their responsibilities".