children black fingernails chop off their hands

Years ago, I remember that the Eurovision Song Contest was on the telly. I was too young to go out, and there was nothing else to do, so somehow I found myself watching it. God knows why. Anyway, one year, sometime in the early-to-mid eighties, they put on a film afterwards. Since Eurovision usually finishes at about one in the morning, I'm quite surprised I stayed up for this one. I remember an American school bus driving into a cloud of fog, and I remember children with black fingernails getting their hands chopped off. For years, I thought this was Children Of The Corn, until I saw it fairly recently and found it utterly devoid of black-fingernailed-killer-children. So I decided to enter children black fingernails chop off their hands into Google, and it took me to this wonderful site. I now know that the film is called The Children (close enough), and another part of my swiss cheese memory is filled in.
Now, if I could only place the horror movie set in a summer camp in which someone is killed on the toilet after the killer drops a hornet's nest into the cubicle, as well as the film in which a teenage girl is terrorised by a spectral black samurai, I'd be happy as a clam.