with a campaign of ethnic cleansing against Croatian civilians. With the Yugoslav People's Army (JNA) lending support to SAO Krajina leadership and the Croatian Police 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 JNA maintained substantial forces in the Croatian capital, Zagreb, throughout 1991. Bombings In August 1991, the Yugoslav Air Force's Counterintelligence Service (KOS) executed a series of activities, codenamed Operation Labrador, aimed at discrediting the new Croatian government. Operation Labrador was planned to include several terrorist attacks that would go hand-in-hand with the activities of Operation Opera — a propaganda campaign devised to feed disinformation to the media. The two operations were intended to portray Croatia as a pro-fascist state. An alternative name for Operation Opera was Operation Opera-Orijentalis, or Operation Opera Orientalis. Operation Labrador was headed by Colonel General Slobodan Rakočević, head of the Yugoslav Air Force branch of the KOS, based in Zemun. In Zagreb, operational control of Labrador was assigned to Lieutenant Colonel Ivan Sabolović, and Major Čedo Knežević. Lieutenant Colonel Radenko Radojčić was tasked with the storage of a substantial quantity of explosives in Zagreb and its surrounding areas and the subsequent planting of explosive devices in designated locations. The explosives and other munitions were stored across several sites. On 19 August, the Jewish Community Centre in Palmotićeva Street in Zagreb, and Jewish graves at the Mirogoj Cemetery, were bombed as a part of Operation Labrador. The explosions caused property damage, but resulted in no casualties. There were no public claims of responsibility for the attack. Aside from the two explosions in Zagreb, agents assigned to Operation Labrador were thought to also be responsible for bombing the Zagreb–Belgrade railway near Vinkovci and a railway line between Glina and Vojnić. The railway attacks have also been ascribed to Operation Opera. Aftermath In the immediate aftermath of the bombings in Zagreb, Josip Manolić, who had just been appointed head of the Croatian intelligence service, claimed Croatian right-wing extremists were responsible. Operation Labrador was abandoned after the ZNG and the Croatian police captured the Yugoslav Air Force headquarters in Zagreb on 15 September 1991, during the Battle of the Barracks. The materials captured inside the facility included codes and computer disks related