Pump-probe double resonance spectroscopy of Rb D-2 transitions are reported for co and counter propagating lasers with tunable frequencies. A perturbative analytical solution of the optical Bloch equations is derived for the five-level atomic system to reproduce the experimental results. The optical pumping effect has been taken into account in the theoretical model. Velocity selective peaks can be observed for all velocity groups of atoms by choosing the appropriate pump frequency. The peaks can be narrowed by varying the lower level hyperfine decay rate. (c) 2007 Elsevier B.V. All rights reserved.