Most existing studies for multiple mobile robots assume that robots can distinguish between other robots and obstacles. However, there would be many cases in which it's not easy for mobile robots to do that in practice. In this paper, we propose a control algorithm for multiple mobile robots without distinguishing between robots and obstacles. This algorithm does not use velocity information of other robots. We also show that the proposed algorithm using such restricted information guarantees similar properties to the existing algorithms on cohesion, velocity matching and collision avoidance in the group. In addition, unlike many previous researches, we demonstrate effectiveness of this algorithm by not only simulations but also experiments. In experiments, since robots don't need to distinguish between other robots and obstacles, laser range finders are used to detect objects around the robot.