On June 16, 1916, the Italians advanced northeast of Asiago, between the Frenzela Valley and Marcesina. Notwithstanding the difficult and intricate nature of the terrain and the stubborn resistance of the Austrians, intrenched and supported by numerous batteries, the Italian troops made progress at the head of the Frenzela Valley, on the heights of Monte Fior and Monte Castel Gomberto and west of Marcesina. The best results were attained on the right wing, where Alpine troops carried the positions of Malga Fossetta and Monte Magari, inflicting heavy losses on the Austrians and taking 203 prisoners, a battery of 6 guns, 4 machine guns, and much material. During the next few days the most fierce fighting occurred on the plateau of Sette Comuni. All Austrian attempts to resume the offensive and continue their advance failed. The Italian advance was scarcely more successful; fighting had to be done in the most difficult territory; strong Austrian resistance developed everywhere. Thunderstorms frequently added to the difficulties already existent. Yet slowly the Italian forces pushed back the invader. On June 18, 1916, Alpine troops carried with the bayonet Cima di Sidoro, north of the Frenzela Valley. Fighting developed in the Boite sector, where the Italians had made some slight gains during the previous days, which the Austrians tried to dispute. Heavy Italian artillery bombarded the railway station at Toblach and the Landro road in the Rienz Valley. Artillery and aeroplane activity was extremely lively during this period. Not a day passed without artillery duels at many scattered points along the entire front from the Swiss border down to the Adriatic. Aeroplane squadrons of considerable force paid continuously visits to the opposing lines, dropping bombs on lines of communication and railway stations. Alpine troops captured a strong position for the Italians on June 20, 1916, at the head of the Posina Valley, southwest of Monte Purche. On the 22d the Italians pushed their advance beyond Romini in the Arsa Valley, east of the Mezzana Peak, and on the Lora Spur, west of Monte Pasubio. On the same day the Austrians counterattacked with extreme violence at Malga Fossetta and Castel Gomberto, but were repulsed with heavy losses. On the 21st a further Austrian attack at Cucco di Mandrielle resulted in a rout. On the 22d the Italians, while holding all the Austrian first-line approaches under heavy fire to prevent the bringing up of reserves, attacked on the entire front, but still encountered a strong resistance. During the night of the 24th the remaining peak of Malga Fossetta, held by the Austrians, Fontana Mosciar, and the extremely important Mandrielle were taken by storm, while the Alpini on the right made themselves masters of the Cima Zucadini by the 22d.