Precise automated video search is gaining in importance as the amount of multimedia information is increasing at exponential rates. One of the drawbacks that make video retrieval difficult is the lack of available semantics. In this paper, we propose to supplement the semantic knowledge for retrieval by providing useful semantic clusters derived from event entities present in the news video. These entities include the output from keywords derived from the automated speech recognition (ASR) and eventrelated High-level Features (HLF) extracted from the news video at the pseudo story level. Fuzzy clustering is then carried out to group similar stories together to form semantic clusters. The retrieval system utilizes these clusters to refine the re-ranking process in the Pseudo Relevance Feedback (PRF) step. Initial experiments performed on video search task using the TRECVID 2005 dataset show that the proposed approach can improve the search performance significantly. Categories and Subj...