Fen River
Around this time, Xun Province continued to be plagued by raids by the ethnic Xiongnu who, while not submitting to either Northern Zhou or Northern Qi, were based within Northern Qi territory and cut off river traffic on the Fen River (汾水, flowing through modern Linfen). In order to cut off the route of their raids, Wei sent his officer Yao Yue (姚岳) to build a fort near the Fen River. Yao initially was fearful that as his troops were building the fort that Northern Qi would launch an attack against him, but Wei warded off Northern Qi attacks by setting up bonfires in the surrounding hills, making Northern Qi forces believe that Yao was being reinforced by a large army, and therefore did not attack Yao, allowing Yao to complete the fort.