Task: Question Generation
Input (English): Passage: The first military action of the Kriegsmarine came during the Spanish Civil War (1936-1939). Following the outbreak of hostilities in July 1936 several large warships of the German fleet were sent to the region. The heavy cruisers  and , and the light cruiser  were the first to be sent in July 1936. These large ships were accompanied by the 2nd Torpedo-boat Flotilla. The German presence was used to covertly support Francisco Franco Spanish State although the immediate involvement of the Deutschland was humanitarian relief operations and evacuating 9,300 refugees, including 4,550 German citizens. Following the brokering of the Non-intervention in the Spanish Civil War to enforce an international arms embargo the Kriegsmarine was allotted the patrol area between Cabo de Gata (Almeria) and Oropesa del Mar. Numerous vessels served as part of these duties including . On 29 May 1937 the Deutschland incident (1937) off Ibiza by two bombers from the Spanish Republican Air Force. Total casualties from the Republican attack were 31 dead and 110 wounded, 71 seriously, mostly burn victims. In retaliation the Admiral Scheer Bombardment of Almería on 31 May killing 19-20 civilians, wounding 50 and destroying 35 buildings. Following further attacks by Republican submarines against the  off the port of Oran between 15-18 June 1937 Germany withdrew from the Non-Intervention Patrol.
Output (English): How many days did the attacks by Republican submarines off the port of Oran last?