Nazi Germany's occupation of Norway and Denmark in spring 1940 meant that Sweden's exports and imports were severely restricted by the 'Skagerack barrier'. Britain needed ball bearings and steel products for its armaments industry and tried to defy the blockade with cargo ships from the Swedish west coast to Scotland. At the same time, the Norwegian High Command in London wanted to transfer male refugees in Sweden to the Allied troops in the UK. A first breakout with five Norwegian ships in January 1941 succeeded, while the next attempt with twice as many boats in March/April 1942 was a disaster. Outside Gothenburg, the German fleet waited, sank three of the ships and captured 236 people, most of them Norwegian refugees, including seven women and a girl. Three ships were sunk by their own crews, two managed to get past the barrage to Scotland and two returned to Gothenburg. These ten ships were called the 'detention boats' after a long British-German process up to the Swedish Supreme Court. In addition to these two British-led blockade runs, there were several little-known Norwegian-British operations from Bohuslän. Most of those who took part were Norwegian citizens, but there were also British sailors and marines stranded in Sweden, plus some Swedes. The prime mover was George Binney, whose clients were Churchill's sabotage organization Special Operations Executive (SOE) and the Ministry for Economic Warfare (MEW).