In this paper we propose a tracking system for wireless sensor networks, which operates on accumulated ranging data from a number of anchor sensor nodes in order to infer the trace and other kinematic characteristics of a mobile target. The nonlinear nature of the ldquotracking with range-only measurementsrdquo problem yields significant challenges. In the proposed system, this problem is modeled as a discrete-time state estimation problem. To achieve tracking of manoeuvring targets, adaptive estimation algorithms and a multi-modal approach to describe the development of the target's state in time are utilized. To solve the estimation problem we employ a particle filter based algorithm. We present simulation results, which demonstrate the ability of the proposed system not only to effectively track manoeuvring targets but also to perform accurately under noisy conditions.