The four-year struggle for control over Nagorno-Karabakh has escalated in recent months to full-scale conflict, leaving in its wake hundreds of civilian casualties. Both parties to this tragic conflict have systematically violated the most basic rules of international humanitarian law. They have engaged in wide-scale hostage-taking, tortured hostages, intentionally targeted, terrorized, and committed other acts of violence against civilians, deliberately shelled civilian objects, forced the civilian population out of villages, and impeded attempts to rescue the wounded. These practices have resulted in the needless deaths of civilians, Azerbaijani and Armenian alike. Helsinki Watch calls on the Armenian Popular Liberation Army of Artsakh, the Azerbaijani National Army, the Azerbaijani militia, and all informal self-defense units to end these practices immediately and, in particular, to return all hostages.