Objects high in the sky for a very short time and then disappeared

I must say, as quickly as they came they disappeared. 4th graders were outside at PE, someone looked up yelled and surprise we had this brief showing of whatever. These objects were extremely high, I'm positive birds don't fly that high. Exactly 1 week before, we witnessed a little bit of a different sighing, unfortunately No Picture/Video. In my 15 years, at this school, I've never experienced this.