In response to progress made by the Americans during Operation Cobra, a German counterattack, known as Operation Lüttich, was launched around Mortain. The main force involved was an assortment of panzer divisions totalling around 300 tanks and any infantry that could be scraped together from the front line. Although the German forces were in far from peak condition, they managed to catch the Americans by surprise with their initial attack on 6 June, taking Mortain and its surrounding villages. American armoured units that were assigned to protect the eastern flank of Operation Cobra sustained significant casualties under pressure from the German panzer divisions, but did not break their line. Allied air superiority meant that the Luftwaffe were incapable of supporting the German advance. Bombing also hampered the advance of infantry and non-armoured vehicles behind the main attacking force of German tanks and the attack soon petered out.
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