Clustering using coordinates and a binary constraint

Hi

I am trying to cluster a set of stations. What I have is all their coordinates but also information whether a certain station has priority or not (binary data). What I want to do is to cluster the data depending on space but I want each cluster to contain a specific number of the priority stations.

So for instance if I have 200 stations of which 50 are priority (1) and 150 are not (0) and I want to create 10 clusters with each cluster having 5 priority stations. Can I use k means to achieve this or is there another clustering method that would be more appropriate.

Many thanks in advance.

Cecilia