July, after suspicions had been raised by increasing amounts of German anti-aircraft fire around the wood. Twenty bombers with seventeen escorts, dropped on the wood and started several fires. On 13 July, a special effort was made to attack troop-trains on the Douai–Cambrai and Valenciennes–Cambrai lines. One train was derailed and overturned near Aubigny-au-Bac and a train was bombed on the Cambrai–Denain line, the British pilots making use of low cloud to evade German attempts to intercept them. German 2nd Army The 12th Reserve Division began to arrive from Cambrai during the afternoon of 1 July but the 5th Division, en route from St Quentin in the south, was delayed by an air raid on the station while entraining, which killed when wagons blew up. By afternoon on 1 July, the survivors of the 28th Reserve Division and Bavarian Reserve Infantry Regiment 6 of the 10th Bavarian Division, had withdrawn to the (second position) from Guillemont to Longueval and Bazentin le Grand. Bernafay and Trônes woods were undefended and the only German reserve was Bavarian Infantry Regiment 16, between Longueval and Flers. The 12th Reserve Division was rushed forward from Bapaume, having moved by train from Cambrai at and marched to the area between Combles and Ginchy, where it was put under the command of the 28th Reserve Division and ordered to recapture Montauban and Favières Wood. Overnight Below ordered the garrison of Fricourt to withdraw; on the south bank reinforcements had been scraped up to occupy the second line, which had stopped the advance of the French Sixth Army but General von Pannewitz, commander of the XVII Corps, was allowed to withdraw from Assevillers and Herbécourt to the third position, on the east side of the Flaucourt Plateau. The power of the French attack, particularly the firepower of French artillery had been a surprise; had been lost on the north bank along with all of the 121st Division artillery on the south bank. During the night news arrived at Below's headquarters, that Thiepval had been held and that had been recaptured. German reinforcements were split up and committed piecemeal, wherever the defence was most vulnerable. Reserve Infantry Regiment 51 was to advance on the northern flank past Combles to Guillemont and enter the north-eastern corner of Montauban. In the centre Reserve Infantry Regiment 38 was to recapture Bois Favières and Reserve Infantry Regiment 23 was to attack between Curlu