This paper presents an application of a clustering algorithm based on gravitational forces to the problem of Web page clustering in a dynamic environment. The proposed algorithm uses a modification of the gravitational algorithm proposed by Gomez et al. but using only the distance measures (a notion of space is not required). This approach is useful when similarities (and/or then distances) between pages can be defined and compute quickly, but the definition of a space is computationally expensive. Experiments with data representing real URL's and sessions are performed, and a comparison with the incremental connected components algorithm, which has been previously used to solve this problem, is done.