In robotic applications of visual simultaneous localization and mapping, loop-closure detection and global localization are two issues that require the capacity to recognize a previously visited place from current camera measurements. We present an online method that makes it possible to detect when an image comes from an already perceived scene using local shape information. Our approach extends the bag of visual words method used in image recognition to incremental conditions and relies on Bayesian filtering to estimate loop- closure probability. We demonstrate the efficiency of our solu- tion by real-time loop-closure detection under strong perceptual aliasing conditions in an indoor image sequence taken with a handheld camera.