I am so sorry, how awful for you and your children.
I see what he did to your children as child abuse, and I would do what I could to make sure the children never have to be with him again.
Please talk to the police as well as your lawyer (lawyer first) and at least put on record a report of what happened. I pray there is a camera somewhere that caught this on film.
Be careful, dear, protect yourself and your children first.
Hugs