The Arabs' first concern was to facilitate the conquest of Sindh with the fewest casualties while also trying to preserve the economic infrastructure. Towns were given two options: submit to Islamic authority peacefully or be attacked by force (), with the choice governing their treatment upon capture. The capture of towns was usually accomplished by means of a treaty with a party from among the enemy, who were then extended special privileges and material rewards. There were two types of such treaties, ""Sulh"" or ""ahd-e-wasiq" (capitulation)" and ""aman" (surrender/ peace)". Among towns and fortresses that were captured through force of arms, Muhammad bin Qasim performed executions of "ahl-i-harb" (fighting men) as part of his military strategy, whose surviving dependents were enslaved.