Time-domain terahertz spectroscopy (TDTS) has been shown to be a promising tool in detection of explosives and explosive related compounds. To date, TDTS for many explosives has been limited to spectral regions < 3 THz. With recent improvements in emitters and sensors of THz radiation, we report the THz absorption spectra over an extended frequency band from 0.5 to 6 THz for four explosives: RDX (1,3,5-trinitroperhydro-1,3,5-triazine), HMX (1,3,5,7-tetranitroperhydro-1,3,5,7-tetrazocine), PETN (pentaerythritol tetranitrate), and TNT (2,4,6-trinitrotoluene). New distinctive spectral features are shown in these materials between 3 and 6 THz. These data may aide in the spectral identification of these explosives. (c) 2006 Published by Elsevier B.V.