Visiting people deprived of their liberty in connection with conflict is a core ICRC protection task. In 2002, the ICRC visited 448,063 prisoners and detainees held in 75 countries. Of these, 149,154 were followed up individually.
International armed conflicts: ICRC visits prisoners of war and interned civilians, who are protected by the Third and Fourth Geneva Conventions respectively. Governments are obliged to allow ICRC access.
Internal upheavals and strife: the ICRC will seek to visit people - either fighters or civilians - who are detained (either by governments or other parties) in direct connection with the situation - these are sometimes known as “security” or “political” detainees.
The ICRC's mandate: the Geneva Conventions and the Statutes of the International Red Cross and Red Crescent Movement.
More on this: ICRC visits to persons deprived of their freedom: An internationally mandated task, implemented worldwide - factsheet (January 2002)