Either Village of the Damned or The Bloodening.
I haven't seen "The Bloodening," so I can't comment on that, but the scene with the brick wall is certainly in "Village of the Damned." Both the British original with George Sanders as the teacher, and the American remake with Christopher Reeve as the teacher. Oh, by the way, I think the British original is the better of the two films.
I also recommend the book upon which both films were based "The Midwich Cuckoos" by John Wyndham.