On October 5, President Tuđman made a speech in which he called upon the whole population to mobilize and defend against "Greater Serbian imperialism" pursued by the Serb-led JNA, Serbian paramilitary formations, and rebel Serb forces. On 7 October, the Yugoslav air force attacked the main government building in Zagreb, an incident referred to as the bombing of Banski dvori. The next day, as a previously agreed three-month moratorium on implementation of the declaration of independence expired, the Croatian Parliament severed all remaining ties with Yugoslavia. 8 October is now celebrated as Independence Day in Croatia. The bombing of the government offices and the Siege of Dubrovnik that started in October were contributing factors that led to European Union (EU) sanctions against Serbia. On 15 October after the capture of Cavtat by the JNA, local Serbs led by Aco Apolonio proclaimed the Dubrovnik Republic. The international media focused on the damage to Dubrovnik's cultural heritage; concerns about civilian casualties and pivotal battles such as the one in Vukovar were pushed out of public view. Nonetheless, artillery attacks on Dubrovnik damaged 56% of its buildings to some degree, as the historic walled city, a UNESCO World Heritage Site, sustained 650 hits by artillery rounds.