the German soldiers that continue to reinforce you

Cross the street to the post office in the north-west.
Take the barn to the northeast, where the overturned wooden tables and haystacks are good cover, and finally attack a small building in the town. After taking the five objectives you receive a new mission to capture the town's tall tower, climb up the vertical ladder with two of your teammates and use the sniper rifle's scope to locate the mortar at the top of the tower.