As the Yugoslav People's Army (JNA) increasingly supported SAO Krajina and the Croatian Police was unable to cope with the situation, the Croatian National Guard (ZNG) was formed in May 1991. The development of the military of Croatia was hampered by a UN arms embargo introduced in September, while the military conflict in Croatia continued to escalate—the Battle of Vukovar started on 26 August. By the end of August the fighting intensified in Lika as well, including in Gospic where fighting to control the city continued through much of September. Although Gospić was controlled by Croat forces, it remained under Serbian artillery bombardment after the battle. The fighting resulted in heavy damage to the town and the flight of the bulk of its population after which only about 3,000 residents remainined. Before the war, Gospić had a population of 8,000, including 3,000 Serbs. Many Serbs previously living in the town fled but Croatian authorities urged them to return through television and radio broadcasts.