During the course of the First Balkan War, the Ottoman Empire's supplies were dangerously limited after the battles in Kirk Kilisse and Lule Burgas and the sea route from the Romanian port Constanţa to Istanbul became vital for the Ottomans. The Ottoman navy also imposed a blockade on the Bulgarian coast and on 15 October, the commander of the cruiser Hamidiye threatened to destroy Varna and Balchik, unless the two towns surrendered.