In Rio de Janeiro so-called drug factions hold control over most of the shanty towns. The State has reacted by 'militarising' its police operations. The result is a humanitarian tragedy that has already cost the lives of thousands of Brazilian citizens. Many of those affected by the violence are of the opinion that the city has become the battlefield of a 'war'. This article addresses the issue of whether the legal concept of armed conflict could and should be applied to such situations.