The Belgian Army Command considered that the German attack on 4 September was a feint and began to plan another sortie, to induce the Germans to recall the troops being transferred to France and to disrupt German communications in central Belgium. German troop withdrawals were observed from A frontal attack was considered to be impossible given the extent of the German trenches but an attack on the eastern flank was considered possible. Two divisions were to remain inside the Antwerp defences, while three divisions and cavalry were to attack towards Aarschot. Important crossings over the Demer and Dyle rivers were quickly taken, Aarschot was captured and by 10 September, the cavalry reached the city of Leuven. The German 6th Reserve Division and IX Reserve Corps were recalled to the region, joining the 30th Division of XV Corps from Alsace, which conducted operations against the sortie between around Brussels. The Belgian advance was stopped and the army retired to Antwerp on 13 September.