1944 French Underground Rebels Against Nazi

In August 1944, ten days before Allied troops entered Paris, the Battle of Liberation began. The French Underground meticulously planned a revolt, marking the first time rebels were ready to act openly. As they prepared, the Germans, aware of the impending uprising, increased their patrols in Paris.

What was the significance of the arm bands worn by the rebels?

How did the Germans respond to the activities of the French Underground?