One of the strongest units, the 8th Garibaldi Brigade, had 8,050 men (450 without arms) and operated in the Romagna area. The CLN mostly operated in the Alpine area, Apennine area and Po Valley of the RSI, and also in the German OZAK (the area northeast of the north end of the Adriatic Sea) and OZAV (Trentino and South Tyrol) zones. Its losses amounted to 16,000 killed, wounded or captured between September 1943 and May 1944. On 15 June 1944, the General Staff of the Esercito Nazionale Repubblicano estimated that the partisan forces amounted to some 82,000 men, of whom about 25,000 operated in Piedmont, 14,200 in Liguria, 16,000 in the Julian March, 17,000 in Tuscany and Emilia-Romagna, 5,600 in Veneto, and 5,000 in Lombardy. Their ranks were gradually increased by the influx of young men escaping the Italian Social Republic's draft, as well as from deserters from the RSI armed forces. By August 1944, the number of partisans had grown to 100,000, and it escalated to more than 250,000 with the final insurrection in April 1945. The Italian resistance suffered 50,000 fighters killed throughout the conflict. Partisan unit sizes varied, depending on logistics (such as the ability to arm, clothe and feed members) and the amount of local support. The basic unit was the squadra (squad), with three or more squads (usually five) forming a distaccamento (detachment). Three or more detachments made a brigata (brigade), of which two or more made a divisione (division). In some places, several divisions formed a gruppo divisione (divisional group). These divisional groups were responsible for a zona d'operazione (operational group). While the largest contingents operated in mountainous districts of the Alps and the Apennine Mountains, other large formations fought in the Po River flatland. In the large towns of northern Italy, such as Piacenza, and the surrounding valleys near the Gothic Line. Montechino Castle housed a key partisan headquarters. The Gruppi di Azione Patriottica (GAP; "Patriotic Action Groups") commanded by the Resistance's youngest officer, Giuseppe "Beppe" Ruffino, carried out acts of sabotage and guerrilla warfare, and the Squadre di Azione Patriottica (SAP; "Patriotic Action Squads") arranged strike actions and propaganda campaigns. As in the French Resistance, women were often important members and couriers. Like their counterparts elsewhere in Europe, Italian partisans seized whatever arms they could find. The first weapons were brought by ex-soldiers fighting German occupiers from the Regio Esercito inventory: Carcano