Local actions of limited extent also occurred on the Trentino front.
On September 15, 1917, greater activity of Austrian artillery provoked a brisk reaction on the part of the Italian artillery in the Upper But and Fella Valley in Carnia. On the Carso Plateau, too, there was considerable artillery action during all these days.
A comparative lull set in during the next week, September 16 to 23, 1917. Though the Austrians had gained some ground on the summit of Monte San Gabriele, this was of little import, because the position was so located that neither side could possibly hold it for any length of time. On the other hand the Italians had captured two more heights on the Bainsizza Plateau near Volnik, which they succeeded in holding against repeated Austrian attacks and heavy artillery fire.
In the Marmolada region, on the night of September 21-22, 1917, by exploding a mine which had been prepared with long tunneling work, Italian parties were enabled to penetrate two advanced Austrian positions and to establish themselves there.
In the neighborhood of Raccogliano and Selo in the Carso, on the same day, the Italians succeeded in making a slight advance.
During September 23, 1917, the railway line in the Bazza Valley, east of Tolmino, was the objective of Italian air forces. In the morning one of the Italian bombarding squadrons arrived over the railway station of Grahovo, about five or six miles eastsoutheast of Tolmino, at a moment when intense railway movements were going on, and four tons of bombs were dropped there. In the night an Italian airship, by dropping numerous high-explosive bombs, greatly damaged the establishments in the neighborhood of Podmelec, midway between Tolmino and Grahovo. At the same time another Italian airship once again bombarded the numerous Austrian troops in the Chiapovano Valley.
In the Monte Nero region, upper Isonzo, the Austrians exploded on September 24, 1917, a powerful mine under Italian positions, upon which they then concentrated violent artillery fire. Prompt and effective barrage fire, hindering the advance of the infantry, prevented the Austrians from gaining any advantage. The damage done was slight.
Another let-up set in for the next few days. However, on September 28, 1917, Italian storming troops made a surprise attack toward the southeastern edge of the Bainsizza Plateau, capturing some of the high ground south of Podlaka and southeast of Madoni, and forty-nine officers and 1,360 men. Subsequent violent enemy counterattacks accompanied by heavy bombardment were repulsed and the positions maintained.