 Complete the following phrase:  At around the time of Mazzucchellis release the secret CLN meetings in the riverside Buco basement room came to an end, due to the increasing risk of detection in the municipality. Mazzucchelli returned to the unit and took a lead in removing this and other groups with which they were networked out of the city and into the mountains on a more permanent basis. The mountains had also become less safe, however, due to the appearance of a German armoured division under the command of SS-Sturmbannführer Walter Reder, still aged only 28, and infamous after the war on account of his leadership role in various mass killings including, locally, 