MHUs are limited in the number of services they can provide and the frequency at which they are available to any one community.  These considerations must be kept in mind when formulating a plan as to how to use MHUs in any conflict or emergency setting.  Du Mortier and Coninx describe their use of MHUs with the International Committee of the Red Cross during the conflict in Columbia in 2005.  In this case, the rebel forces refused to allow access to the Ministry of Health in the country to citizens in areas they held. 