Daylight raids by Bomber Command had ceased by 1941. The British bomber arm concentrated on rebuilding for the night area offensive as an alternative. Whereas six "gruppen" were available for night fighter operations, they daylight defence of Germany rested mainly on anti-aircraft guns, I./JG 3 and I./JG 1, supported by provisional units of limited combat effectiveness. This remained the case from 1940 through to 1942. The German fighter units faced occasional raids against coastal targets. One exception to this was an attack by 54 Blenheims on Cologne power stations on 12 August 1941. The lack of combat action was in contrast to JG 2 and JG 26 battled RAF Fighter Command's Circus offensive over France and Belgium, which were no threat to the German Reich. For the most part, JG 1 operated over an area considered a backwater. The Stabsschwarm operated alone, since it had no component "gruppe" of its own; the semi-autonomous I. "Gruppe" which had never been under Schumacher's command became III./JG 27 in July 1940.