More details from the BBC:
Mr Ashraf said that the teacher at the centre of the row, Arfa Iftikhar, "perhaps inadvertently skipped a page of the book and ended her handwritten text with some lines from the next chapter, which is about street beggars".
He said that Mr Farooqi fired Ms Iftikhar on Tuesday, the first working day after the Eid holidays, after the school management received calls from parents pointing out the error.
Correspondents say it is not clear who distributed copies of the error, but as is often the case in Pakistan, the issue was seized upon by Islamic hardline groups who went on the offensive.
The authorities have now said that if it turns out the school administration was not at fault in sanctioning the actions of the teacher, action will be taken against those in the mob who took matters into their own hands and destroyed the school.