This paper presents an effective methodology for the control of a group of mobile robots moving in desired formations. Virtual head robot tracking and three-point l-l controllers incorporated with reactive control schemes are proposed here to overcome the cases when the control law is undefined and subject to potential inter-robot collision. In order for the whole group to enter a desired formation, a general procedure is suggested in the initialisation stage. Advantages of our approach include the establishment and maintenance of any formation from arbitrary initial conditions with collision avoidance for a large group of mobile robots. The approach is validated through simulation cases to illustrate the capability of handling singularities and avoiding collision in a group of N robots. © 2006 IEEE.