We discuss a novel multiscale approach to the detection of moving objects in a sequence of images. The approach is based in part on a multiframe generalization of an optical flow estimation algorithm previously developed by two of the authors. This algorithm provides an extremely efficient multiscale method for estimating optical flow in an image sequence and allows for the temporal accumulation of motion information. Moving objects in a sequence correspond to discontinuities in the true optical flow and, as a result, the residual image associated with the estimated optical flow can be used as a basis for detecting these objects. We propose an approach to detection based on morphological processing of the residual image, and illustrate its potential on real data.