We address the problem of estimating direction-of-arrivals (DOAs) for multiple sound sources using a single acoustic vector sensor (AVS) in an enclosed room environment. It is well-known that multi-source DOA estimation in an enclosed environment is challenging due to room reverberation, environmental noise and overlapping of the source spectra. In this work, we propose a multi-source DOA estimation algorithm which exploits co-location of the sensor elements in AVS. We identify time-frequency (TF) zones of the received signals in which only one source is dominant with a high signal-to-reverberation ratio. DOA estimation is then achieved via the use of clustering of the Hermitian angle feature. Simulation results show that the proposed DOA estimation algorithm is robust to both reverberation and environmental noise.