May, court-martials were established to try those that were arrested in possession of weapons, and those found guilty were immediately executed by firing squad. The precedent for this brutal repressive measure against Serbs had already been established by the Germans. It was clear from the outset that the NDH weapons laws were not being enforced as strictly against Croats as they were against Serbs. Securing the border between eastern Herzegovina and Montenegro was considered a high priority due to concerns that the Montenegrin Federalist Party had revived Montenegrin claims to parts of the NDH that had been promised to the Kingdom of Montenegro in the 1915 Treaty of London. The Italians handed over the administration of eastern Herzegovina to the NDH government on 20 May 1941, following the signing of the Treaties of Rome, which ceded formerly Yugoslav territory along the Adriatic coast to Italy. The Italians did not immediately withdraw all their troops from the region. The NDH moved quickly to establish its authority in the towns and districts of eastern Herzegovina, which included appointing mayors and prefects, the creation of local units of the Ustaše Militia, and deploying hundreds of gendarmes, Croatian Home Guards and Ustaše Militia units from outside eastern Herzegovina. These forces were brought in to maintain order. The academic Professor Alija Šuljak was appointed the Ustaše commissioner for eastern Herzegovina. On 20 May, the recently formed Home Guard battalions began to deploy into the Adriatic Command area. On 27 May, 6 officers and 300 gendarmes of the Sarajevo-based 4th Gendarmerie Regiment were deployed into parts of eastern Herzegovina. They established platoon strength posts in Nevesinje, Trebinje, Gacko and Bileća, with their headquarters also in Bileća. The Dubrovnik-based 2nd Gendarmerie Regiment established posts in Stolac and Berkovići. The headquarters of Adriatic Command was transferred to Mostar in late May, and General Ivan Prpić was appointed as its commander. By 29 May, the battalions of Adriatic Command were in their garrison locations: the 6th Battalion at Mostar, the 7th Battalion at Trebinje, and the 10th Battalion in the Dubrovnik area. The other two Adriatic Command battalions were deployed to Knin and Sinj far to the west. The 18th Battalion was allocated as a reserve and was garrisoned in Mostar. Main Ustaše Headquarters was tasked to recruit one battalion for duties within the Adriatic Command area. Home Guard battalions had a standard structure, consisting of a headquarters company,